Die drei ??? und der Karpatenhund

In the organizer's words:

The detective trio Justus Jonas, Peter Shaw and Bob Andrews, better known as the three ???, receive a desperate call for help from gallery owner Mr. Prentice (Ulrich Tukur). They are told that sinister things are happening in his apartment and the detectives have to find out what or who is behind it. But the case takes an unexpected turn when one of Mr. Prentice's valuable works of art, the Carpathian Dog, is stolen.