"And after dinner, what did you do?"
"I fastened the shutters and doors, came up here and undressed."
"Are you in the habit of bolting yourself into your room?"
"Yes, I lock my door every evening."
"What time was it when you went to bed?"
"Ten at latest."
"And then?"
"Then I went fast asleep, but in the middle of the night I was waked by a strange noise. It sounded like a scratching at my door. I gave a shout and banged my fist on the partition."
"Why?" asked Juve, surprised.
The American explained: