Campions young and old, extended family members and loyal friends are gathered at the Dorchester Hotel to celebrate Albert Campion's seventieth birthday - along with some intriguing, unrecognizable guests. Who exactly are the mysterious, aristocratic, scar-faced German, Freiherr Robert von Ringer, and the elegantly chic Madame Thibus - and what is their connection to Mr Campion?

Campion has decided the time has come to enthral his guests with his account of his wartime experiences in Vichy France more than twenty-five years before, but in doing so he unveils a series of extraordinary events. Why here, and why now? Not least as Campion's shocking revelations have repercussions which reverberate to the present day, putting one of his guests in deadly danger . . .