ten o'clock
Occasionally he comforted himself with a cautiously smoked cigarette , but mostly he lay patiently watching the trap that was to lure his prey . At one o'clock each morning he rose , returned on his beat , went to bed , and fell instantly asleep . On the fifth night there was a variation of the programme . It was between nine and ten o'clock that Jack heard the hoot of an owl . He sat up instantly , eyes and ears keyed for action . The back door of the sod-house opened , and through the night stillness floated the faint strumming of a guitar . Jack did not doubt that it was the answering signal to show that all was safe .