There's also the oddity that Genji didn't say anything to Rosa about the three going to the chapel. He just said that they went to Natsuhi's room, even though he supposedly never saw them after they left.
Hm, is there a possibility that the room key actually got picked up earlier in the day, when the first twilight was discovered?
Regarding the first twilight, I'll see your theories and raise one of my own: Someone unlocked the chapel on October 4th prior to 1pm. The Halloween party was set up by one or more of the servants at that point, and then one of them met with Rosa and Maria and handed over the key, leaving the door unlocked. The adults were able to enter without trouble, and they were killed there sometime around midnight by a person who knew about their meeting, again leaving the door unlocked. In the morning, Genji lied to Rosa about the chapel being locked to maintain the locked room illusion, not realizing that there were dead bodies inside since those weren't a part of the original plan.
Last edited by LyricalAura; 2010-01-27 at 16:53.