In the third and final series of `The Tunnel', the Anglo-French crime drama follows Commander Elise Wassermann and DCI Karl Roebuck as they deal with a man attacked by a plague of rats and three British children who vanished from their home in Kent. When a burning fishing boat is found on the Channel, the British and French police work together again to put a stop to the murders. Wassermann and Roebuck get closer to danger as they try to find the truth behind the killings, finding the incident is not just a political statement but a personal one too.