Gaston Leroux,
The Mystery of the Yellow Room
“ They must be very valuable to have been put away in a safe, and the key to which to be of so much importance. Perhaps a thought of blackmail occurred to him as a useful possibility in helping him in his designs on Mademoiselle Stangerson. He quickly made a parcel of the papers and took it to the lavatory in the vestibule. Between the time of his first examination of the pavilion and the night of the murder of the keeper, Larsan had had time to find out what those papers contained. He could do nothing with them, and they were rather compromising. That night he took them back to the château. ”
