Semir is pursuing a young couple on the motorway who have stolen a sports car when a jeep breaks through the police cordon and crashes into the other car. One of the occupants of the jeep limps into the nearby forest with a sports bag and disappears there. A little later, Semir and Tom learn that the occupants of the jeep are bank robbers who have just robbed a branch. Andrea has been able to establish the identity via Interpol: the fugitive is a certain Pieter van Heerlen, his colleague who has been taken to hospital, a Romanian named Tadescu. The doctors determine that he is suffering from a particularly dangerous subtype of diphtheria. Van Heerlen has meanwhile taken Semir hostage and continues his escape with him. The district president orders the SEK to intervene immediately because he fears an epidemic caused by Van Heerlen, who is also ill. Tom does everything he can to help his partner before the hostage situation ends in a bloodbath.