The number of Mr.Delora's apartment is 157.

Here, by the bye, monsieur, is a key." I took it and put it in my waistcoat pocket.
"You will ascend by the lift from the smoking-room to the top floor," Louis continued.

"You can then descend by the other lift to the fifth floor, and walk boldly into the sitting-room.

The door on the right will be Mr.Delora's bedroom, and of that there will be, after midnight, a key upon the mantelpiece in the sitting-room." "But Miss Delora ?" I asked.

"What of her?
The sitting-room connects, also, with her apartments." "Mademoiselle will be told something of this during the evening," Louis answered.