The Great Pearl Secret by A. M. Williamson and C. N. Williamson

A maid opened the door leading from a bedroom to a salon of the “royal suite” at Harridge’s Hotel. Dusk had fallen, and entering, she switched on the electricity. The room, with its almost Louis Seize decorations, was suddenly flooded with light; and to her surprise the Frenchwoman saw a slim black figure nestled deep among cushions on a sofa before the fire. A small white face, with a frame of terra-cotta hair crushed under a mourning toque, turned a pair of big black eyes upon her.