The first programme shows how sharks are the ocean's great predators, living in every ocean and hunting in every way. Blacktip sharks hunt in huge packs and herd fish into baitballs, tasselled wobbegongs are ambush hunters, Greenland sharks live under the arctic ice, and whitetip reef sharks are the masters of hunting at night. The finale shows the great white in its hunt for fur seals off the coast of South Africa.

Sharks are more than just hunters. Only now are discoveries revealing a hidden side to their character. They have an intricate social life, complex courtship rituals, surprising ways of bringing up their young and extraordinary powers of navigation. They can forge relationships with the strangest of partners, even us! This is the secret life of the shark.

Sharks are among the most misunderstood predators on the planet, but an international team of scientists is trying to change that. Their research is revealing that sharks can be sociable and intelligent, and they could even help solve some of the toughest medical challenges of the 21st century. However, their breakthroughs come just as many sharks face extinction. Science may now be the only way to save them.