A good yarn with an intriguing idea behind it and the French detective, Saturnin Dax in charge. A youngish professor and his bride join an older honeymoon couple for a picnic jaunt in the Forest of Fontainebleau with all but the younger bride aware of the stakes involved. Paul disappears in the natural labyrinth, then Elizabeth vanishes and becomes a prisoner. Dax, in unwinding the mystery, turns up murder and violence, buried jewels and Nazi loot, and provides a nick of time solution. Keen on the scent Parisian policing.