Two years ago, on the treacherous Kali River, high in the mountains of Northern India, Jeremy Wade unearthed the mother of all fisherman's tales and the ultimate freshwater horror: a super-sized freshwater fish turned man-eater. Jeremy takes on the biggest, toughest challenge he's ever faced as he heads back to the Himalayas to separate fact from fiction and track down the monstrous beast.

In the darkest depths of the Amazon lurks a dinosaur. Legends tell of an evil spirit inhabiting an enormous fish. Taller than a man, it is covered in scales and crushes its prey with a tongue made of bone. Jeremy Wade has encountered this creature once before, and he came out second best. He's taking no chances in the rematch.

A man swallowed whole by a fish. A body eaten alive from within. Another penetrated in a most unnatural fashion, and yet more with multiple stab wounds. Jeremy Wade is in pursuit of these notorious killers to discover the facts — to determine if their crimes are real and their methods as gruesome as reported.

Reports of an attack on a swimmer in a lake close to Berlin is the starting point for an intense and shocking investigation. Wade travels to Germany where he meets modern-day victims of a beast that has been raising its snout above the surface of fresh waters in Europe regularly over the past 700 years. Investigations travel to Spain where Wade discovers firsthand that the wels catfish is a living, breathing aggressive predator growing to man-eating proportions capable of everything depicted in medieval records and more.

In 1976 a packed coach crashed into the Amazon killing 39 people. By the time the bodies were pulled out by rescuers some had been so viciously mutilated by piranha they could only be identified by their clothes. Tracking down survivors and eyewitnesses of piranha attacks, Jeremy Wade reveals why the piranha fills our nightmares.

No fish inspires the same terror as the shark, a creature with an insatiable hunger for brutal violence. But at least these killers are confined to the oceans. Or are they? Expert angler Jeremy Wade investigates whether it's possible for sharks to live in freshwater, and if so just how far inland these vicious predators will bring their reign of terror.

In the Deep South is a river monster with the reputation of a devil. Blamed for a series of violent attacks on humans, this creature is said to be as vicious as a shark and as big as an alligator. The authorities said it should be annihilated, but not all are so quick to condemn it. Extreme angler Jeremy Wade heads to Texas on its trail in an attempt to uncover the facts behind this animal's notoriety. Helped by local expertise and with his own wits honed sharp, he finds new ways to reveal the truth about the monster alligator gar.