A mysterious killer is lurking in the steely waters off the east coast of Canada. Scientists are baffled by all the corpses on the beach. The seals bear bizarre spiral wounds which have led to one theory that one of the most elusive of all sharks is responsible, the Greenland shark. Scientists from the Canadian Shark Research Laboratory and the Apex Predator Program in the United States will try to solve the puzzle of the dead seals once and for all. Please note: this title shows images of animal corpses and shark attacks on seals.