Calladine fell for her . . . hard. They'd met that night dancing at the Semiramis Hotel and he had fallen under her spell almost immediately. All too soon the evening ended and Calladine thought he'd seen the last of her. But a few hours later she's on his doorstep. Her name is Joan Carew and she needs his help.

Joan quickly admits to him that she had just come form trying to steal an expensive pearl necklace. She'd made her way into the suit of her intended mark at the Semiramis Hotel but there was someone already there. Thieves who grab her. The last thing she remembers is struggling with them as they try to bind her. A few hours later she came to alone in the room except for the dead body of the woman who had owned the pearls.

Calladine agrees to help her immediately. This lovely woman can't be a murderer . . . can she? Enter Inspector Hanaud one of France's finest detective. If anyone can get to the bottom of this case he can.