As the whole world watches, Peter and the cold-case group lead Sweden's biggest manhunt in decades. Barbro returns to Österbymo to look for answers relating to that disappearance, which they now realize was the killer's first victim. It seems like all is lost, when suddenly the killer contacts Peter for one last game of cat and mouse.
Following a mental breakdown, Detective Peter Wendel is tasked with creating an elite team of investigators to crack cold cases. When the police find a note on a dead body that claims Sweden's most notorious serial killer is a fraud, Wendel gets a chance to redeem himself, but only the dregs of the force are available to work the case. Under pressure to mobilize quickly, Wendel is forced to hire two cops who hate each other, plus a forthright woman...