Shock for Kunz: The dead man, to whom the police were called, is his former colleague Helmut Walz from the robbery department. Brandtner learns from Commissioner Sabine Kogler that Walz was suspended a few months ago for excessive alcohol consumption. Walz's drunkenness began after he arrested the notorious bank robber Hanusch, known as "the mole", but was shot to the cripple in the process. Hanusch later managed to escape, he fled to Brazil, but Walz did not give up the search for him even when Hanusch was declared dead. Thanks to Rex, Brandtner now secures a bullet case at the site of Walz's murder, on which is a fresh fingerprint of Hanusch. Rex and Brandtner follow the trail of the "mole" - deep down into the catacombs of Vienna...
