Season 1

The body of a woman was found at the border crossing in the Straits of Dover Tunnel. When the body is removed, it is discovered that the upper and lower halves of the body belong to different people. It becomes clear that this is a double murder disguised as a single body. The team is challenged to investigate a complex case involving politics.

The perpetrators use the Internet to publish the “second truth”. Karl and Elise are astonished to learn that the killer is using a police server in England. Karl and Elise continue their investigation into the deaths of a prostitute and a Member of Parliament, but their investigations take them to different sides of the Channel.

Susanna survives an addiction case and is attended to in the hospital by her brother Stephen. A pensioner appears on the murderer's website and his suffering is broadcast live. Karl and Elise head to France to identify the victims. Journalist Danny calls himself a “truth terrorist” and spreads the truth about the treatment of the elderly.

TT asks the four wealthy people for donations and threatens that Jean-Claude will die if they do not donate. Elise discovers the slight movements of Jean-Claude in the live video, discovers that the vibrations are related to the sound of a high-speed train, and begins to match them with the surrounding refrigerators.

Benji kills his psychiatrist and tries to take his own life, but fails. He confesses that “no one has assigned me a mission...” When he announces the “third truth,” the police realize that Sophie holds the key to finding TT, and they desperately try to find her before the killer does. And while in custody, Benji successfully commits suicide...

Young people are set on fire and burned to death one after another while still alive. Suspecting him of being a “truth terrorist,” the priority is to apprehend Stephen Beaumont. Anthony's body is found, and Elise finds evidence of Anthony's murder in Susanna's apartment. Steven boards a cross-channel ferry and is arrested for Anthony's murder.