After the events of season 2, a court case and a possible prison sentence are looming over ex-cop Bob. Ferry is released from prison but finds out that his position at the top of the XTC-world is taken over by a new, stronger and more intelligent gang, which is led by the Dutch-Turkish married couple Serkan and Leyla Bulut.

When a young undercover agent is murdered, the police realise that they have a mole in their midst. Patrick Diericks makes Bob an offer: he can make his court case disappear if Bob goes undercover again and can unmask the traitor inside Serkan's gang as a civilian infiltrator. Bob reluctantly takes on this life-threatening mission in order to get his life back on the rails and to secure a future with his new family. But then he encounters Ferry Bouman...