A Catholic clergyman retrieves a priceless church cross from master thief Flambeau
A master art thief has been stealing works of art throughout Europe and one day manages to steal a priceless cross from Father Brown’s church.
With the assistance of Lady Warren and over the exasperated objections of his bishop, Father Brown is determined to find the cross, locate Flambeau and in the process, if he can, save Flambeau’s soul.
The search takes Father Brown to Paris and the French countryside, down into catacombs and into Flambeau’s chateau. At last there is a confrontation, followed by a resolution that involves Lady Warren as well as Flambeau.