Ten o'clock
Josephine was usually incorrigibly slow , and Sally May always needed reminding that the devotion bell would ring in two minutes ' time . To-night clothes were neatly arranged ready for the morning , rooms were in impeccable order , hair was properly brushed , and there was no mad rush to be at one 's own door when the fatal bell sounded . At last `` Lights out '' bell rang and silence descended on South House . Ten o'clock , and the prefects put out their lights , only the tiny red fire-escape lamps shone dimly at intervals down the corridor . Eleven o'clock , and the night watchman had creaked by on his way to East House . The way was clear . Out of bed slipped the conspirators .