Publisher's Synopsis
The story is set in London, after the events described in At the Villa Rose. Ricardo, the dilettante amateur detective, is sitting at his breakfast table in Grosvenor Square when he is interrupted by his great friend Gabriel Hanaud, the French professional detective.A visitor is unexpectedly shown in: a fashionable young man named Calladine whom Ricardo has not seen for several months. Visibly distressed, Calladine blurts out a fantastic tale of having attended a ball at the Semiramis Hotel the night before, and having met a young woman dressed in a distinctive masquerade costume who had early the next morning turned up unannounced at his chambers seeking sanctuary. He reports that the young woman, Joan Carew, an opera singer, confessed that she had been tempted by a valuable pearl necklace worn by one of the hotel guests, and that she had crept into her room to try to steal it. On entering, she finds that she had inadvertently disturbed and been seen by two masked men who were also there to steal the pearls. She faints, and when she comes round discovers that the men have disappeared and she is alone with the necklace's dead owner. She rushes over to Calladine's chambers.
