Jeremy Wade investigates a case in Nepal that sounds strangely familiar -- a lone fisherman dragged off his feet and into a mountain river by an unseen creature, thought to be the original river monster, the goonch catfish.

On a volcanic island in the Pacific, terror grips a fishing community when something in the water leaves a trail of bloody victims in its wake; the only clues they have to the attacker's identity are the large puncture wounds it left behind.