half past eleven
`` I do n't assert that it was ; but with the bolt on Gertrude 's door , the cat in the kitchen , and the rat-trap on the garret stairs , I am strongly inclined to anticipate a peaceful night . I will watch for a while , however , and you can go to sleep . '' She went to sleep , and I watched . I lay till half past eleven with my eyes staring at the dark , wide awake and undisturbed and triumphant . At half past eleven I must confess that I heard a singular sound . Something whistled at the keyhole . It could not have been the wind , by the way , for there was no wind that night .