A burnt corpse is discovered and Alex and Rex are on the case. What they don't know is that the victim is Hans Tomek who has returned to Vienna after making a lot of money in America. His twin brother is waiting and kills him to assume a better life.

A serial killer is on the loose in Vienna and is killing women on each full moon. In order to catch him dumping the next victim in a cemetery, Alex has them staked out, but the next morning another woman is found dead.