A horrific crime has been committed at the Villa Rose in Aix-les-Bains, France. A wealthy woman has been strangled, a fortune in jewelry is gone, and the young Englishwoman who was her companion has gone missing. The natural conclusion is that the Englishwoman played a role in the crime, but her fiancé, Harry Wethermill, induces the cleverest of French detectives, Hanaud, to take on the case in an attempt to prove her innocence. Along with his friend Mr. Ricardo, it becomes his task to find the girl and solve the murder At the Villa Rose!