Markus receives a visit by Annika Hallgren from the Katrineholm police who suspects that a mechanic convicted of murdering an elderly man is innocent. The same day the murder occurred the victim's son appears in the city but has since then disappeared without a trace. The question is where the son is and if he had motive to murder his father?
Fia is in hospital after the hostage crisis and the very first night she experiences an unpleasant incident when her roommate cardiac arrests and dies. The autopsy shows that the woman received an overdose of morphine and a nurse is suspended. Fia is convinced that the nurse is innocent and commits herself to investigating the case.
A convicted murderer runs away during a leave of absence and when he does not get a hold of Markus, he takes Roger, Fia and Belal as hostage. The man claims to be innocent of murder and want Markus to help him prove it. But no one knows where Markus is located so Anna is left upon her own devices to try and save her friends.
Amanda's life completely changed the morning when she fell asleep while driving and as a consequence a woman and her daughter was killed. Amanda was convicted and is serving a prison sentence. The OD-group decides to review the case. For Roger, it turns out to be a complex matter because his past relationship with Amanda.
A woman appeals to Markus and his team that they will review her boyfriend's case. The boyfriend was convicted of murder a few years earlier in a case which Markus' ex-wife, Ulrika, was prosecuting. The OD-group reluctantly takes on the case and Markus begins to suspect that is Ulrika hiding something.
A woman is found murdered and the murder appears to have great similarities to a murder that occurred a year earlier. The father of the first victim, contacts the OD-group because he does not believe that the man who pleaded guilty is the real offender. But if the man is innocent, how does he know so much about how the murder was carried out?