A young woman, Claudia Vogler, takes a small stray dog home one night. In her home she is attacked and strangled to death. Rex befriends the only witness to the murder in hopes that the little dog will lead him to the killer.

After the police have raided a man's home for illegal guns, they don't realise that they haven't collected two of them. When the man is released on bail he returns home, gets one of the guns and returns to the station where he murders one of the officers involved in the raid.