Delta In The Darkness

“The incident occurred on June 6th, between 8:00 and 9:00 in the afternoon. The victim was strangled in her room. The room’s sole door was locked from the inside. The door was on the mansion’s second floor, in a position easily visible from the large banquet hall below. On the night in question, many people happened to be present in that hall. Despite this fact, not a single one of them witnessed anyone other than the victim enter or exit that door. On the opposite side of the room was a large window, but it had also been locked from the inside. Horokusa Junpei, the detective, had been keeping watch over that window for the entire time the incident is thought to have taken place, and furth...