The plot follows detectives Karl Roebuck and Elise Wasserman working together to find a serial killer who left the upper-half body of a French politician and the lower-half of a British prostitute in the Channel Tunnel, at the midpoint between France and the UK. They later learn that the killer—who comes to be nicknamed the "Truth Terrorist"—is on a moral crusade to highlight many social problems, terrorising both countries in the process
A Maltese type dog belonging to the mother of Charlie Moreau is found dead after his father finds Charlie in a game of hide and seek in the garden. How Charlie exactly kills the dog isn't quite known as it happens off screen though it's likely the dog could have been smothered or had his neck broken in an attempt to stop him barking.
Another dog - a West Highland terrier named Brian, survives a carbon monoxide attack on the Roebecks' family home, thanks to his own barking waking Karl and Laura up.
in episodes 102 or 103 and 201 a group of men start taking their clothes off, surrounding a trapped woman who is screaming, then the camera cuts away and there's no continuing audio. each time we later see the woman very upset. in 206 the same general thing happens but to a young man who is drugged.
A plague of rats infesting the Tunnel are later destroyed by pest control.
Then one rat that is sent to the British police station in a box gets stamped to death by Elise.
Another dog - a West Highland terrier named Brian, survives a carbon monoxide attack on the Roebecks' family home, thanks to his own barking waking Karl and Laura up.