GSI follow up a weapon trail that leads right into Kavkaz mafia headquarters on the west coast. GSI member Niklas Saxlid is the one in the group who is specialized in undercover operations, and he has penetrated Kavkaz' activities. But suddenly something happens and Niklas disappears.

When a well-known crime boss is murdered by a sniper in front of his family, Beck and his team are challenged to discover which one of his many enemies could be responsible for the crime.

When JW becomes a drug runner in order to maintain his double life, his fate becomes tied to two other men: Jorge, a fugitive on the run from both the Serbian mafia and the police, and mafia enforcer Mrado, who is on the hunt for Jorge.