When an explosive device planted by a suspected sleeper terrorist detonates at a bus stop in a suburb of Essen, the Federal Criminal Police Office (BKA) immediately arrives on the scene and takes command of Mick's precinct. This doesn't sit well with the last cop—he doesn't like being told what to do and also sees the case very differently from the pompous officials in Wiesbaden. Mick and Andreas begin to ask questions, irritating not only the assassin's friends and widow, but also the BKA.

Of all places, a long-sought-after serial arsonist tampers with Mick's car. The perpetrator turns out to be a minor girl: Julia Brinkmann. Mick and Andreas aren't responsible for arson—until they find a dead body in a burned-out car wreck. It's Greta Gerlach, the ex-wife of a construction magnate, at whose wedding Greta had drunk plenty of champagne and then taken a nap in her parked car.