Rex, still depressed about Moser's death, finds himself being passed from Böck to Höllerer. A corpse in the river is found but has no identification. A passerby spots a bag, and it proves to contain the only evidence in the case. Alexander Brandtner is called in to replace Moser, having lost his own dog Alex goes to see Rex and together a new partnership is formed.

Three people get together and decide to kill the person who has been blackmailing them. But when one of the three wants out, will Alex and Rex be able to solve the first murder quick enough to prevent another?