When his brother disappears, a man visits the remote country house where he was last seen. While the host seems outwardly friendly and his niece more demonstrably so, there's a feeling of menace in the air with the overhanging legend of Lavinia Morley, the Black Witch of Greymarsh.

Our heroes find themselves at the famed Cannes Film Festival to help foil a plot to murder a former American union boss cum government witness, Kyle Sander. Suspects include the beautiful Marissa and boyfriend, who have a few surprises in store. Lord Sinclair and Danny then travel to Switzerland, where they have to help an elderly Duchess protect her jewels by finding proof of past marriage to a prince.