D.C.I. Cardinal's plans to smash the gang of his old adversary Gus Clifford are thwarted by the discovery of a dead man in Northumberland. He assigns D.S. Grout to investigate the murder while he continues to lead the hunt for Clifford. Grout's investigation begins at Hadrian's Wall, but a second murder leads both men to the center of an international art-smuggling organization on the Bodensee. Cardinal and Grout must uncover the identity of the killer before he strikes again, and stop the Clifford gang.