Munch takes on the case of Adam Astier, a young man accused of killing his girlfriend. He actually turned himself in to the police and confessed to the crime. But Munch quickly realizes that certain things just don't fit. Adam behaves oddly, reciting his confession as if he learned it by heart. When Munch gets Adam evaluated by a psychiatrist, she discovers he has Asperger's syndrome, a rare form of autism. Learning that people with Asperger's are incapable of lying makes her job even tougher. Apparently she's defending a guilty man. And yet, some of Adam's statements turn out to be false. How can someone with Asperger's, who can't lie, also contradict himself by stating two different truths? Munch has to track down the person who manipulated Adam and forced him to confess to a crime that he doesn't seem to have committed. Meanwhile, Munch learns that Judge Montjoie has proof she stole sealed evidence. So she breaks into the Judge's office to find out what that paralyzing proof is. But all she finds is an empty file. On other fronts, Clarisse is still hoping to get a court hearing to regain custody of her son Nathan. But Aurélien, thinking he can help out, ends up putting her whole case in jeopardy. Bellanger has to help a rugby player with heart disease find a new job, while dealing with an unexpected request from his daughter Pauline: she wants to go to boarding school. Both Bellanger and Munch don't like it at all.
