LKA target investigator Nora Weiss can book a success when, after a long search, she is able to confront and arrest the alleged sex offender Karl Strasser. She is all the more angry when Strasser is released from prison a day later due to a formal error. At the same time, a respected Syrian doctor is killed in a bomb attack in Lübeck. Together with her colleague Simon Brandt from the Lübeck Criminal Police Office, Nora is under extreme time pressure to investigate whether the murder was a terrorist attack. But a first clue leads her to the widow Karin Brendner. Their eleven-year-old son Paul had been operated on by the recently murdered doctor a few months earlier and died as a result of the surgery after being released from the hospital early.
Karin Brendner blames the doctor for her son's death, and his older brother turns out to be an explosives expert. When Nora and Simon want to question him, he flees and goes into hiding. Now the target investigator is asked to track down the fugitive as quickly as possible, since other people involved in the fateful surgery may also be in danger. Meanwhile, Nora comes dangerously close to Strasser, who has been released from prison.