The story revolves around detectives Karl Roebuck and Elise Wasserman as they join forces to track down a serial killer. This murderer has left the top half of a French politician’s body and the bottom half of a British prostitute’s body in the Channel Tunnel, precisely at the border between France and the UK. As the investigation unfolds, they discover that the killer, dubbed the “Truth Terrorist,” is on a mission to expose various societal issues, instilling fear in both nations along the way.