Alex, Böck and Rex decide to treat themselves to a balloon ride over Vienna. While floating over the city, they witness a bank robbery and the subsequent murder of a passerby who tries to stop one of the robbers from getting away.

A body is found in a park which appears to have been mauled to death by a dog. Dr Graf however confuses the situation when he tells Alex that the autopsy reveals that the death was caused by a wolf, which has been extinct for over 200 years.