ten o'clock
She goes to bed tired and she sleeps peacefully into death without waking . She is probably asleep within ten minutes , before her own warmth has penetrated through sheet and blanket to the mattress beneath and so destroyed her . Suppose that she is dead in half an hour . She retired to rest at ten o'clock ; she is called at seven ; the room is presently broken into and she is then not only dead , but cold . The demon has gone to sleep again under its lifeless burden . Now had she been stout and well covered , there had hardly been time for her to grow cold , and those who came to her assistance might even have perished , too . But she is a little , thin thing , and the heat has gone out of her .