“Madame arrives, the theft is discovered. The chambermaid demands to be searched, with a good deal of righteous indignation, and leaves the room without a stain on her character. The imitation necklace with which they have provided themselves has been concealed in the French girl’s bed that morning by the chambermaid⁠—a master stroke, ça !”

“But what did you go to London for?”

“You remember the card?”

“Certainly. It puzzled me⁠—and puzzles me still. I thought⁠—”

I hesitated delicately, glancing at Mr. Opalsen.

Poirot laughed heartily.