[Game] Umineko - Spoilers, Theories, Interpretations

[Judoh]

Originally Posted by Tresspasser

One thing that's puzzling me is the first twilight in EP 1. When it began, it showed you where everyone was on the island. But Nanjo's location was a mystery, I was wondering if anyone had a theory for that due to the fact that no one seems to have mentioned it yet.

No one really knows. From episode 2 though I think he's usually on the second or third floor. So probably a guest room or Kinzo's room. For some reason though I don't beleive Nanjo wants to be there for the conference. I get the feeling he just wants to wait things out until it's over, but I'm not sure whether or not he knows much about what's going on.

[Jan-Poo]

Still in the case that in the end we'll find out that the murderer is Nanjo I bet someone will say that: "Nanjo was hinted to be the murderer because he was the only one whose location wasn't shown!"

[Oliver]

Originally Posted by Jan-Poo

Still in the case that in the end we'll find out that the murderer is Nanjo I bet someone will say that: "Nanjo was hinted to be the murderer because he was the only one whose location wasn't shown!"

...or he doesn't exist because he does not have a location. If anyone on the island has to not exist, I'd rather it be Nanjo, he's almost a non-character anyway.

Seriously though, with the way the story is structured, it's very hard to say which is a hint and which is a deliberate lie, and the amount of information to process is monstrous. Current English translation itself is twice the length of War and Peace. If you look hard enough, you can find hints to support almost any kind of theory, including the deliberately silly Orbital Particle Beam Shot.

I'm afraid it's not hints we should be looking for.

[Renall]

The anime shows Nanjo asleep in a chair somewhere at midnight in ep1. Of course, people's locations in the midnight montage should not necessarily be taken as gospel, nor does it necessarily matter where everyone is at midnight. The murderer, especially in ep1, has lots of time to commit the crime.

Originally Posted by Judoh

I'm just wondering do we really need a safe haven for someone to survive? I guess we assumed that, but couldn't Eva or whoever just take Krauss's boat and go to Niijima? I don't think it's really as far away as we might think.

Whether a safe haven is needed or not, we're told Kuwadorian was safe and that Eva was found there by the police. I don't see any reason for the people who said that to lie, and it would be a perfectly plausible place to find someone as it would be the only remaining "safe" structure and it has a port, so the police would (on Kawabata's information) probably set there first to conduct their search.

[KnightOfTwo]

Regarding the 1998 world, I am rather interested in the status of the chapel. When Ange goes to Rokkenjima she doesn't mention anything about it, nor is it shown, nor does anyone else mention anything about it. While it could be unimportant as Kuwadorian wasn't shown either, or it simply is unimportant. I find myself curious since the chapel is likely going to be a big point in the endgame.

[Raiza Sunozaki]

Originally Posted by Oliver

Seriously though, with the way the story is structured, it's very hard to say which is a hint and which is a deliberate lie, and the amount of information to process is monstrous. Current English translation itself is twice the length of War and Peace. If you look hard enough, you can find hints to support almost any kind of theory, including the deliberately silly Orbital Particle Beam Shot.

I'm afraid it's not hints we should be looking for.

Or the equally deliberately silly Marisa Culprit Theory.

In any case, this just goes to show how Ryuukishi's tendancy to get really long-winded while writing creates an abundance of hints as well as a ridiculously long story. Twice the length of War and Piece? Wow. That kinda makes me proud for reading all through Umineko. Maybe I'll marathon the entire series once I've got all the English patches.
On a side note, an at max fifty-episode anime series doesn't quite seem to give Umineko much credit to me, now that I have a idea of long it is.

Originally Posted by Renall

Whether a safe haven is needed or not, we're told Kuwadorian was safe and that Eva was found there by the police. I don't see any reason for the people who said that to lie, and it would be a perfectly plausible place to find someone as it would be the only remaining "safe" structure and it has a port, so the police would (on Kawabata's information) probably set there first to conduct their search.

And I completely agree with that. I was just having some fun debating it's existence. But on a serious note, I do sort of doubt it's habitability, considering it's likely Kinzo would've abandoned it after Beato the Second's death. Then again, it's equally likely that Kinzo, being obsessed with her, would've kept in tidy shape, for when his beloved returned.
I wouldn't put it past Kinzo.

[KnightOfTwo]

Originally Posted by Raiza Sunozaki

But on a serious note, I do sort of doubt it's habitability, considering it's likely Kinzo would've abandoned it after Beato the Second's death. Then again, it's equally likely that Kinzo, being obsessed with her, would've kept in tidy shape, for when his beloved returned.
I wouldn't put it past Kinzo.

He did have the servants clean the honored guests room even though he never let anyone stay in it, as well as keeping the chapel clean but telling everyone to stay away from it. I wouldn't put it past him to keep Kuwadorian in nice condition.

[imaginari]

Originally Posted by Jan-Poo

I reached the same conclusion when I made my timeline. The Kuwadorian is older than the mansion, and I suspect that it was there even before Kinzo bought the island. It might as well be the very reason Kinzo decided to buy the island and transfer the whole family there.

I've suspected this for a long time. Kinzo said that Beatrice showed him the way to the gold, didn't he?

[Jan-Poo]

Originally Posted by Oliver

Seriously though, with the way the story is structured, it's very hard to say which is a hint and which is a deliberate lie, and the amount of information to process is monstrous. Current English translation itself is twice the length of War and Peace. If you look hard enough, you can find hints to support almost any kind of theory, including the deliberately silly Orbital Particle Beam Shot.

Yes that was my point. It's way too easy to claim "there were hints to reach conclusion X", where such hints were absolutely indistinguishable from any of the other thousand non-hints and do not have a really logic relation with what they are supposed to hint at.

P.S: you weren't serious about "war and peace", right? I don't think umineko really reached that length...

Originally Posted by KnightOfTwo

Regarding the 1998 world, I am rather interested in the status of the chapel. When Ange goes to Rokkenjima she doesn't mention anything about it, nor is it shown, nor does anyone else mention anything about it. While it could be unimportant as Kuwadorian wasn't shown either, or it simply is unimportant. I find myself curious since the chapel is likely going to be a big point in the endgame.

Absolutely nothing is mentioned about the status of the Mansion, the chapel, the guesthouse, and the garden.

From the game we only have confirmation that the port doesn't exist anymore and that the path to reach the mansion is interrupted by a landslide.
Apparently Ange needs to climb down to proceed, but if she does then she can't go back.

There is a sentence that always bugged me, and was the main reason I always thought that there is really no Mansion anymore:

Originally Posted by Ange

I'll be back soon. Today, our main goal is Kuwadorian. ......After I deliver this, I'll come right back.

She hasn't seen Rokkenjima in 12 years. The place where she's going is where her family died. It's the place where the unfortunate accident happened, which totally changed her life. It's also the place where she holds a lot of distant happy and nostalgic memories.
And yet she only wants to go there, deliver something, and then go back quickly to see the "main goal" Kuwadorian (where she's never been before).

Mansion apart, what about the guesthouse? Not any curiosity about the chapel? They don't even deserve a mention?

I really can't see any logic explanation except that the explosion destroyed all of them.

Think also about these facts:

-When Kinzo's books were auctioned it was explained that they survived the accident because they were in Kuwadorian. Hinting that the general public expected that no book could have survived.

-Eva was found in a far away place from the site of the incident. Even if an explosion occurred, why she didn't rush back afterward to look for survivors? At the very least she should have done that to look for George or George's body.

-A lot of bodies (if not all of them) are totally missing. A total disintegration of a body is not what you would expect from a normal explosion. And yet bodies are missing and it doesn't appear as if the fact is seen as strange, hinting that the kind of accident that happened can well explain why nothing is left of the victims.
If not, why such disappearances are accepted so easily? A single body missing, okay... two... three could still be understandable, but four and more? I'd be a lot suspicious if it were me.

-Ryuukishi said in an interview that the incident affected the terrain. He also affirmed that the fact that Kawabata was unable to dock at the port should have hinted this. (despite the fact the port is quite far from the Mansion).

-Ryuukishi confirmed that the Mansion's remains are missing.

[Oliver]

Originally Posted by Jan-Poo

P.S: you weren't serious about "war and peace", right? I don't think umineko really reached that length...

I am serious. I've been counting.

War and Peace is about 2 million characters long, give or take, including spaces. An average fantasy or science fiction novel is around 500-600 thousand. Most Harry Potter books exceed a single million each.

The combined length of all translated English text in Umineko scripts, which is easy to compute because OnScripter requires it to be marked with backticks, is over 4 million characters.

Originally Posted by Jan-Poo

-A lot of bodies (if not all of them) are totally missing. A total disintegration of a body is not what you would expect from a normal explosion. And yet bodies are missing and it doesn't appear as if the fact is seen as strange, hinting that the kind of accident that happened can well explain why nothing is left of the victims.

Actually, it keeps me puzzled anyway. There's few accidental explosions that can leave no traces of a body at all.

Volcano eruption might do all these things, but it's a natural process that is extremely hard to deliberately cause. Various military explosive charges leave bits and pieces, lots of them, with the exception of fuel-air explosives which have more or less no way to end up on the island. Gas explosion works like fuel-air, but there's no way the island would have a stockpile of gas big enough to actually change the landscape - blow buildings to bits, sure, burn everything, sure, but actually moving this much earth, no.

That explosion is actually extremely annoying. There's so little specific information on it's character, when it should be public knowledge in Ange's time. Official explanation of the incident absolutely can't be "something blew up, we don't know what it was except that it's an accident". They need to say at least what blew up and make a good guess why. Yet everybody is awkwardly avoiding the topic, including Ange and anyone else who should know, and it doesn't come off as obvious information they don't use because it's common knowledge, it sounds like someone censored Ange's memory and cut off chunks of conversation.

I'm not even sure why this information needs to be kept away from the reader at such an expense. Is it because we would immediately guess who Beatrice is if we had the slightest idea on the true nature of the explosion? Gee, probably not. We have lots of theories that might fit (all not terribly satisfactorily) and the list of people who could have set them in motion and be 'Beatrice' is half the island for each of them. Unless they're all wrong, that is. There might be one explosion cause theory from which the identity of Beatrice inevitably follows and it would be the right one.

But all the reasonable ones have been exhausted by now, which would normally mean one of them is correct. What's left is Hinamizawa syndrome-level nonsense.

[Tyabann]

Originally Posted by Oliver

it sounds like someone censored Ange's memory and cut off chunks of conversation.

This is perfectly plausible at this point.

[Oliver]

Originally Posted by Kaisos Erranon

This is perfectly plausible at this point.

It is, but - why? To conceal the nature of endgame event.
Why conceal the nature of endgame event? To prevent us from discovering the nature of Beatrice, which would be naturally deducible if we knew the nature of endgame event.

We now have a lot of theories on the nature of endgame event, and from none of them the identity of Beatrice follows cleanly. Therefore, none of them is the one that was actually concealed from us and they are all wrong.

But we have tried all the ones that made sense. Therefore:

The true endgame event theory is one that heretofore was not treated seriously because it does not make sense.

And this is the conclusion I don't like.

[Tyabann]

Why are you so certain that discovering the nature of the endgame event would reveal the identity of Beatrice? And why are you also certain that any theories put forth thus far are correct?

[Krystalwitch]

Originally Posted by Kaisos Erranon

Why are you so certain that discovering the nature of the endgame event would reveal the identity of Beatrice? And why are you also certain that any theories put forth thus far are correct?

That's the only way we have to solve this. As for me, I'm not planning to just sit and see how this ends. I wanna give my best and try to solve the mystery. And I think most of the people here think the same way as me. So, our best way is to share theories and opinions, and try to get something out.

As for that, IMO, we should start getting on more focused points, like "first we talk about the stuff in EP1", because I think that way, we can get a better idea. I dunno, it's just my opinion, but I think I'm not wrong at all....

Of course, I'm talking about discussing one thing, but using all the information we have, including TIPs, Novel and interviews.

What do you guys think?

[Oliver]

Originally Posted by Kaisos Erranon

Why are you so certain that discovering the nature of the endgame event would reveal the identity of Beatrice?

• The official nature of the accident has to have been determined, or it would never be declared an accident. The official investigators have to settle on something even if it isn't true. Anything else looks bad and pleases the ufologists.
• It is highly important to the entirety of Ange's narrative, Ange's fighting against the official interpretation, she's looking for alternatives.
• At no point, Ange clearly says what the official interpretation is. No other 1998 character does either. But there are multiple points in their conversations where saying it would be perfectly natural and expected.
• In all those points, it's as if a chunk of conversation is missing, and various descriptive words have been replaced with neutral equivalents.
• But there is no way these characters would hide something so important. Whoever censored Ange's account, whether it's the author, or any of the meta-characters who have the ability, has to have been doing that deliberately.
• Which means that the hypothetical censor was hiding something from Battler, if they weren't hiding something from us, which is more or less the same in this case.
• That means that the correct endgame event theory allows one to deduce something the censor would rather not have us deduce.
• What information could possibly follow from a correct endgame event theory? The most obvious one is who is behind it. An endgame event theory that is completely blank for anyone in 1998 because they weren't there, but allows the more knowledgeable us (or Battler) to know who could do it, and therefore did it, is perfectly reasonable.
• It is perfectly obvious that in Ep4 Battler dies by endgame event, which allows us to associate the perpetrator of endgame event with Beatrice in the most direct fashion so far, leaving aside the question of intent.
• Therefore, knowing the true nature of endgame event would allow us to deduce the identity of Beatrice too easily, which is why it's shrouded in such secrecy. Any endgame event theories that are not connected with a specific perpetrator of such are therefore wrong.

Originally Posted by Kaisos Erranon

And why are you also certain that any theories put forth thus far are correct?

I am certain they're the only ones I find plausible and likely -- there aren't many of those. Therefore, if the real one is not among their number, it wasn't plausible to me when I considered it.

Since whichever theory fits the above-recited logic chain is not among the likely ones, none of which allow to pinpoint an identity of the perpetrator, it has to be among the unlikely and silly ones.

[Jan-Poo]

@Oliver

I think you need to see this with the right perspective. Umineko isn't just a mystery novel, it's a game. Or at least this is how Ryukishi sees it.
In a game you need to create various challenges to entertain the players. Some of these challenges aren't strictly necessary to reach the end of the game their just there to give the players additional content to play with.
So you don't need to think that anything that is mysterious is relevant for the main plot. It might be, but it might not.

I think that it's absolutely clear that since EP1 Ryuukishi wanted everyone to believe that the police found some kind a slaughterhouse scenario which would clearly point to a murderer.
Just read the ending scroll of EP1 it was cleverly constructed for that end. Hell, how many fell for that? Almost everyone I'd say. Even the generic term used to refer to "the site of the incident" is so much commonly used to refer to "crime scene" that the witch hunt opted for this translation, even 'though there is actually no reference at all about any crime.

And the finishing blow was telling that this event later became known as "the rokkenjima murder mystery" although we know this is how wild speculators and "witch hunters" call it, and not the more serious media.

Seeing through this kind of deceptions is what Ryuukishi consider "scoring" in his game. And he also stated that he doesn't want to give a readily available answer to those who didn't find the truth. He wants to extend the "winners" monopoly over certain truths as max as possible. Which is why he couldn't tell you right away that what happened in Rokkenjima was some kind of incident. He left tons of hints in EP4, and when he thought it was apparent enough he just dropped the bomb (quite fitting metaphor...).

This kind of pattern can be seen everywhere in umineko. Ryuukishi doesn't reveal things out of the blue. He first slightly hints them, then he heavily hints them, and only after they have been speculated over and over again he confirms them.

The lack of information about the incident in EP4 can be just a narrative expedient created for this end.


But let's just suppose that it's as you say and there's a deeper reason for all this. How exactly knowing the kind of incident that happened can give us hints about Beatrice's nature? I can't even imagine a scenario where I could get some relevant information. Maybe you can help with that?

[rogerpepitone]

Regarding Shkannon and their shifts:
There are two different parts to a shift:
- what times a servant is supposed to be on duty at the mansion / guesthouse, and what times they are free
- when on duty, what they are supposed to be doing at the mansion / guesthouse

Most likely, the first is mostly fixed (Kanon is on duty Mondays, 5-7 PM, Renon Tuesdays 5-7 PM, etc.), while the second can be rearranged at any time. When Krauss and Natsuhi are mentioned as fiddling with the schedules, it's the second kind they're changing.

IIRC, it's stated that there are usually only 2 or 3 servants on Rokkenjima at any time. With the Fukuins still being kids, they probably have very restricted schedules, while Genji and Gohda are probably full-timers. (Kumasawa is stated to be part-time, but she probably works longer shifts than the Fukuins.) In the absence of visitors, there probably isn't more than 1 Fukuin present at a time.

[Oliver]

Originally Posted by Jan-Poo

This kind of pattern can be seen everywhere in umineko. Ryuukishi doesn't reveal things out of the blue. He first slightly hints them, then he heavily hints them, and only after they have been speculated over and over again he confirms them.

The lack of information about the incident in EP4 can be just a narrative expedient created for this end.

You see, this is one case where it's not very expedient. It's a linguistic problem.

When I want to talk about subway bombings, I will say 'subway bombings', not 'incident' or 'accident'. When I want to talk about the time when my neighbour's house blew up because he left the gas open, I will say 'gas leak', not 'accident'. The usage of the unspecific 'accident' in such cases is restricted to fairly narrow cases:

• When I need to clearly delineate 'accident' from something deliberately premeditated. Then it's 'accident' once and 'subway bombings' from then on. I may say 'My neighbour has an accident', but then I'll add 'he had a gas leak', and when anyone asks me 'where were you when your neighbour had an accident', I will normally respond with 'huh, what accident?' because internally it's filed as a gas leak.
• When I don't know what the hell happened and assume it was an accident. But if I don't know anything about it, I don't say things about it, I ask questions about it.
• When the event is complicated and involves a lot of things that happened in an extended stretch of time, such as a 'hostage incident'. Some qualifier will still normally be present and having a 'murder accident' would be problematic.

What in particular Episode 4 does a lot is omitting any qualifiers as long as possible even when the result is a statement that makes no sense. Certain anime and manga series loved to play with this, defining some 'kono hito' early on and then using it as it it were the name of some completely undefined character which, supposedly, attracts mystique along the way in this manner. It has been many years since this stopped working and even jokes about this are going out of fashion -- people don't really talk that way. This is not narratively expedient, this looks silly, there have to be limits. It's like trying to write a book without using the letter "e" - possible, but gruesome.

Which is why I feel that it may well be that Ryukishi really wanted to tell the story of Ange's pity party, but realised that giving us the police incident report in any serious detail would amount to giving the answer away, because with everything else we already know it's enough. That would really spoil the crowning final puzzle of Ep4!

So he just concentrated on Maria's diary and censored over any other characters who would otherwise want to talk about the incident report.

Originally Posted by Jan-Poo

But let's just suppose that it's as you say and there's a deeper reason for all this. How exactly knowing the kind of incident that happened can give us hints about Beatrice's nature? I can't even imagine a scenario where I could get some relevant information. Maybe you can help with that?

Stop thinking of plausible things and you'll immediately start finding things that could work. For example, very few people had a chance to play on the island as kids unattended, and that would be Rosa and Jessica. If what blows up is a secret underground military base with a remaining stockpile of explosives, so that the plateau the mansion is on just implodes, only Rosa, Jessica and Kinzo are likely to be able to do anything to trigger it and Kinzo is dead.

Is it plausible? Not really. Would telling us that be a huge gamebreaking hint? Oh yes, I'd tell you where Kinzo got his gold then.

Let us continue thinking backwards. If my guess is true, then the endgame event mechanism fits the following conditions:

• First, what we already know about it:
  • It's catastrophic enough to change the landscape.
  • It always happens on the same time.
  • It happens regardless of who is alive or dead.
  • It can be thought to be an accident.
  • It is probably deliberately generated anyway.
  • It probably can be disarmed.
• Only a very limited number of people have the means to cause it, rather than motive. I.e. it can't be that character X has prepared the bomb which multiple characters can trigger, even if 'Beatrice' didn't make the bomb, she is the only one who can trigger it and thus be considered the 'killer'.

This way any scenarios where anyone can cause an explosion are declared unfitting. Only those remain:

• Based on things only a few people could have a chance to know. (Secrets, special expertise)
• Based on resources only a few people can have access to. (Large sums of cash, unique objects)

Any ideas, beside scrapping the whole chain of thought, ofcourse?

[Jan-Poo]

Well I'm not sure if this linguistic expedient is as bad in japanese as it sounds in english. They tend to omit stuff a lot more than we do.
For example you mentioned "kono hito", but that definitely sounds a lot less strange than "that person" in english. Just think about Virgilia and how she never refers to Beatrice by her name. She always calls her "ano ko" (that child), that in western culture is simply silly but it's not really that strange in Japan.

Plus most of the times the "unfortunate accident" is mentioned it's by some narrator. When it's people talking about that, my impression is that they don't want to mention what happened because it's painful to remember or because it's already clear what happened.
Just think about the 9/11. I've just said two numbers but I guess you perfectly understood what I'm talking about. Nobody says "the terrorist attack at the world trade center", everyone is pretty much used to call it 9/11. And if this was a story you would say "why everyone is omitting to say what this "9/11" is?!"
Because everyone already knows too well what it is, there's no need to repeat it every time.

If what blows up is a secret underground military base with a remaining stockpile of explosives, so that the plateau the mansion is on just implodes.

It's been speculated already since quite a while. And I can't really see any other way to explain how several tons of explosives destroying a whole house and slaughtering a whole family can be called "accident" or "incident".

But still this doesn't tell us much about Beatrice since it isn't clear if Beatrice has anything to do with the accident to begin with. Plus everyone could have come across this military base in a way or another.

First, what we already know about it:
It's catastrophic enough to change the landscape.
It always happens on the same time.
It happens regardless of who is alive or dead.
It can be thought to be an accident.
It is probably deliberately generated anyway.
It probably can be disarmed.

The fact that it always happens at the same time is not very relevant, imho.
If you believe in the author theory, then this incident only happened one time and it's a core rule of the fictional stories created afterward. If you believe in the many-world interpretation that might still be a core rule. The incident just has to happen at a precise time, and since it's definitely relevant, it's only natural that it cannot change.
Anyway the fact it can never change fits more with a natural disaster scenario than with a human triggered one.

However I have my doubts that this marks the end of each game. We know that the games end at midnight, but does that definitely means that incident happens at that precise time? It might be plausible, but I see no certain proof of this relation. The way I see it the unfortunate accident could have happened at any time in 6th October from 0:00 AM to 6:00 AM

I'm also not certain about the last two, but you correctly used "probably".
However the last, in particular, is not necessary because we know everyone can be saved simply by taking refuge in Kuwadorian.

[Raiza Sunozaki]

Originally Posted by Oliver

Spoiler for Large post is large.:

You see, this is one case where it's not very expedient. It's a linguistic problem.

When I want to talk about subway bombings, I will say 'subway bombings', not 'incident' or 'accident'. When I want to talk about the time when my neighbour's house blew up because he left the gas open, I will say 'gas leak', not 'accident'. The usage of the unspecific 'accident' in such cases is restricted to fairly narrow cases:

• When I need to clearly delineate 'accident' from something deliberately premeditated. Then it's 'accident' once and 'subway bombings' from then on. I may say 'My neighbour has an accident', but then I'll add 'he had a gas leak', and when anyone asks me 'where were you when your neighbour had an accident', I will normally respond with 'huh, what accident?' because internally it's filed as a gas leak.
• When I don't know what the hell happened and assume it was an accident. But if I don't know anything about it, I don't say things about it, I ask questions about it.
• When the event is complicated and involves a lot of things that happened in an extended stretch of time, such as a 'hostage incident'. Some qualifier will still normally be present and having a 'murder accident' would be problematic.

What in particular Episode 4 does a lot is omitting any qualifiers as long as possible even when the result is a statement that makes no sense. Certain anime and manga series loved to play with this, defining some 'kono hito' early on and then using it as it it were the name of some completely undefined character which, supposedly, attracts mystique along the way in this manner. It has been many years since this stopped working and even jokes about this are going out of fashion -- people don't really talk that way. This is not narratively expedient, this looks silly, there have to be limits. It's like trying to write a book without using the letter "e" - possible, but gruesome.

Which is why I feel that it may well be that Ryukishi really wanted to tell the story of Ange's pity party, but realised that giving us the police incident report in any serious detail would amount to giving the answer away, because with everything else we already know it's enough. That would really spoil the crowning final puzzle of Ep4!

So he just concentrated on Maria's diary and censored over any other characters who would otherwise want to talk about the incident report.



Stop thinking of plausible things and you'll immediately start finding things that could work. For example, very few people had a chance to play on the island as kids unattended, and that would be Rosa and Jessica. If what blows up is a secret underground military base with a remaining stockpile of explosives, so that the plateau the mansion is on just implodes, only Rosa, Jessica and Kinzo are likely to be able to do anything to trigger it and Kinzo is dead.

Is it plausible? Not really. Would telling us that be a huge gamebreaking hint? Oh yes, I'd tell you where Kinzo got his gold then.

Let us continue thinking backwards. If my guess is true, then the endgame event mechanism fits the following conditions:

• First, what we already know about it:
  • It's catastrophic enough to change the landscape.
  • It always happens on the same time.
  • It happens regardless of who is alive or dead.
  • It can be thought to be an accident.
  • It is probably deliberately generated anyway.
  • It probably can be disarmed.
• Only a very limited number of people have the means to cause it, rather than motive. I.e. it can't be that character X has prepared the bomb which multiple characters can trigger, even if 'Beatrice' didn't make the bomb, she is the only one who can trigger it and thus be considered the 'killer'.

This way any scenarios where anyone can cause an explosion are declared unfitting. Only those remain:

• Based on things only a few people could have a chance to know. (Secrets, special expertise)
• Based on resources only a few people can have access to. (Large sums of cash, unique objects)

Any ideas, beside scrapping the whole chain of thought, ofcourse?

I have to both agree with you, Oliver, on some points, but on others, I agree with Jan-Poo.
First of all, where it is obviously intentional, like a subway bombing, people are not going to call it an accident. However, in a case where clues indicating an intentional explosion are not apparent, such as a gas leak or the Rokkenjima Explosion, people usually go with the assumption that it is an accident. "An absence of proof does not indicate a proof of absence," yes, but in such a situation as the Rokkenjima Explosion, I doubt it would be even difficult, let alone easy, to find clues indicating a premeditated explosion. It would near impossible, especially if the explosion did originate deep underground.
But yes, it is very suspicious that in the entirety of Ange's back-story, we did not even get a definite confirmation of an explosion. All we got was a sob-story, an idea of how magic in Umineko works, and confusing hints like how Eva apparently died in a similar way to Kinzo.
I have an idea to why Ange's memory feels incomplete, though I'm not sure how it might help. Think about it. Since Meta-Battler is the main narrator, it's reasonable to think that all narration, even the narration of characters which are not him (with the exception of a few Meta-Beatrice narrations) are just him narrating what Beato is narrating to him via the gameboard's story.
But if this is true, how do we get Ange's narration, which doesn't take place on any gameboard? I think it's Battler, once again, narrating a narration which is give to him. As Ange was being turned into hamburger meat at the end of Episode 4, Battler says that all her memories, the struggles she went through after no one came back from the conference, flowed into him. So once again, he is receiving a narration, and all Ryuukishi is doing is having that narration shown to us at various moments throughout the Episode.
However, like how Beato can modify the narration she gives Battler through the gameboard, isn't it possible for someone to modify Ange's narration that Battler receives. My immediate suspicions place this on Bern, but it seems out of character, at the time, for her.

On the bomb, I've got a feeling that it's set up before the gameboard begins. Why? Because it always happens. In my opinion, things that are set up or happen before the gameboard begins are constants (such as Shannon breaking the island's mirror, or Kinzo's death), but things that happen during the game are variables, and are liable to change, as they do in each Episode. Note that the game is in play for forty-eight hours, from midnight on the fourth to midnight on the sixth.
If I'm right, that means the culprit is either someone on the island, or has an accomplice who is regularly on the island. Which isn't much of a problem, since most people theorize that some number of the servants/Nanjo are accomplices to the mastermind.
But yes, Beatrice must be the once who triggers the explosion. After all, in Episode 4, Beatrice is the one who kills Battler. So she must be the one who can trigger the bomb.
However, both Jessica and Shannon, who seem to be the only characters left that can be Beatrice, rarely ever survive until endgame, which means if Beatrice is the one who triggers the explosion, it must be done at an earlier point. My reasoning indicates a timed explosion, set to detonate unless the Epitaph is solved, but this is incredibly clichéd, so I'm reluctant to decide on it.