The musician Udo Lindenberg (played by himself) is kidnapped during the party after a concert. Nobody realises this until the next day, when he doesn't show up in time for a rehearsal. Since the police believes this is only a promotion gag, private eye Kuhlmann (also played by Udo Lindenberg) has to be hired to find him in time.
Direction
Lindenberg directing himself playing himself twice. Unhinged.
Acting
Eddie Constantine's Lemmy Caution cameo is pure cinephile catnip.

Director
Udo Lindenberg
Trivia, insights & behind the scenes
This came out when Lindenberg was Germany's biggest rock star—imagine Springsteen making a noir comedy where he kidnaps himself.
Eddie Constantine's appearance connects this directly to Godard's 'Alphaville,' making it an accidental art-house multiverse moment.