Rex moved to Rome with Fabbri. There, a third man is shot with the same weapon as the two Austrians in the allegedly closed case. Fabbri asks Viennese colleague Erika Hedl to come to Rome this time.
Art critic Kurt Castro has been murdered in his home. It is alleged from sources in the police that it has to do with homosexual prostitution. But is it so?
After causing the death of his mistress, Mantovani takes her diary. Walking on the street, the bag is stolen from him . The thief later tries to blackmail him