In the high Arctic, the team meets the bowhead whale, the longest-living mammal, and the Greenland shark, the longest-living vertebrate.

In the high Arctic, the team takes on the challenge of the polar bear to figure out what the changing habitat could mean for its future.

The team is in the Caribbean to find out how great hammerhead sharks navigate their migrations and how adapted they are to life in the shallows.

The team is in the Azores to tag a deep-sea giant — the six-gill shark — and learn more about its nightly patterns on the hunt for food in the abyss.

The team dives into the depths of the mid-Atlantic to reveal the secret life of sperm whales and discover its hidden prey.

In the Caribbean, the team reveals great secrets in the lives of the humpback whale, witnessing a mother defend her calf in the ultimate ocean battle.