[Renall]

Originally Posted by Key Board

At this point I'm certain the following is not the master mind:

Battler, at least, Battler as we know him
Krauss. Too damn inept to plan anything. Might be an accomplice, though
Natsuhi. Delusional, but not master mind material. Might be an accomplice
Maria. Too young
Kumasawa. Too old
Eva. The was most likely an accomplice during one of the games, but she's not the master mind. The episode 3 ending happened because an argument broke out between her and the master mind. ( Hideyoshi was killed among other things )
Hideyoshi. See above
Ange. Obviously... she's more a victim

I can't agree with Krauss (he could have an unusual talent for murder, and his bad sense of timing might lead to variations), Kumasawa (so she's old, so what?), and Hideyoshi (we know too little about him).

Originally Posted by Kaiba

You know, just thinking about it, does Battler ever actually see the attack upon Natsuhi's door in the first episode - ye olde "you can't trust anything Battler doesn't see" schpiel here, but I want to make sure.

Battler never really sees anything Natsuhi claims exists, which has some interesting implications given her instability. Is she actually being tormented, or is she making all that up out of desperation and crazy?

Originally Posted by ~Diru~

Well about Natsuhis room:

-Natsuhi's room was exactly the same, just like usual

I like how nobody seems to find it interesting that her room was ransacked and trashed, yet Beatrice says it was "just like usual." Is Natsuhi's room regularly trashed? Does she tear the room apart looking for something on the night of the 4th? After ep5, I can see her having a room in some kind of exploded state.

Originally Posted by Dlanor .A. Nox

It's an action taken on the spot, a plan not put into effect until the time arrives. Same with Eva's and Hideyoshi's the door was probably solid when Genji and Kanon were knocking on it.

Something I'd not considered: Is it possible to take a door completely off its hinges, and does that count as opening it?

Not that this really helps with locked doors. Maybe. I suppose you can take a deadbolted door off its hinges and replace it very carefully. But you'd need time and a screwdriver or power tool, so this is only really a feasible excuse for something like a First Twilight where the killer has plenty of time.

I agree, however, that the "only a key can lock this door" red truths have to be somewhat flexible to accomodate locking and unlocking from inside. Most doors simply do not have keyholes on both sides of the door; they're unlocked and locked by turning the bolt. Gohda opens the (locked!) chapel door during the ep2 magic scene (which means they may never have actually been in the chapel, but still, it suggests something), and tries to lock the door to Natsuhi's room through a similar maneuver. If the door can be locked while inside, certain closed rooms are easier while others are no different (because the killer was already excluded from being present, the room was stated to be searched, the room had nowhere to hide in absent an illegal secret area, etc.).

EDIT: Also, I like how the "perfect" closed room never seems to be used because it's too good: Kinzo's study. Throw something in there along with both keys, and the room is completely impossible to enter except through the windows (and nobody is allowed to do that until ep5 where they actually do, although at the time I think both keys weren't in the room). It's a possible resting place for Kanon in ep4, since Battler was completely unable to find him anywhere else.