A filmmaker forges an unusual friendship with an octopus living in a South African kelp forest, learning as the animal shares the mysteries of her world.
After years of swimming every day in the freezing ocean at the tip of Africa, Craig Foster meets an unlikely teacher: a young octopus who displays remarkable curiosity. Visiting her den and tracking her movements for months on end he eventually wins the animal's trust and they develop a never before seen bond between human and wild animal.

Life goes to extraordinary lengths to survive this immense realm. A 30 tonne whale shark gorges on a school of fish and the unique overhead heli-gimbal camera reveals common dolphins rocketing at more than 30km an hour. Descending into the abyss, deep sea octopus fly with wings and vampire squid use bioluminescence to create an extraordinary colour display. The first ever time-lapse footage taken from 2,000m down captures eels, crabs and giant isopods eating a carcass, completely consuming it within three hours.

In changing seas and oceans, cephalopods like the cuttlefish and the giant Pacific octopus must rely on their remarkable intelligence to survive. Their alien appearance comes with astonishing resources, independence, and invention. And there's still so much to learn about these rarely seen legends of the deep.

This second episode is a captivating exploration of the ocean's wonders and mysteries. It reveals how a significant part of our planet remains unexplored, primarily due to its vast water coverage. The film emphasizes the extraordinary discoveries awaiting every journey below the water's surface, with over a thousand new species identified annually. Home to 80% of all animal life on Earth, the ocean's diverse habitats host a range of surprising behaviors and life-and-death struggles, often hidden beneath a serene exterior.
The shallow tropical seas, appearing as paradises, are actually arenas of intense survival battles. Predatory lionfish, with their patient hunting tactics, and clown frogfish, using a unique fishing rod-like dorsal fin as a lure, demonstrate the ocean's complex food web. The documentary also explores the kelp forests off the North American coast, revealing their role as nurseries for young horn sharks. Amidst these underwater forests lurk giant sea bass, wolf-eels, and various sharks like houndsharks and broadnose sevengills, posing significant threats to the smaller inhabitants. The episode takes viewers to the twilight and midnight zones of the ocean, unveiling alien-like creatures such as the siphonophore, glass squid, and gulper eel, adapted to the extreme conditions of deep waters. The journey concludes with the moving story of the pearl octopus, whose devotion to her eggs in the challenging deep-sea environment is both heartwarming and heartbreaking.
This episode is not only a showcase of the ocean's diverse inhabitants but also a reminder of the urgent need to understand and protect this vast, mysterious, and vital part of our planet.

The coast is the dynamic border between land and sea; powered by the tides and thrashed by waves, this is a world of continuous change. Opportunities never last long here, so hunters are always in a race against time. The coast is the only place on the planet where predators from air, land and sea come together. Dolphins that leave the safety of the sea to fish, walking octopuses, ingenious monkeys, fishing wolves and the greatest gathering of feeding humpback whales come to the coast to hunt. For all, timing is everything.

We may be smart, but we're still discovering animals have countless skills, every bit as impressive. In a world full of unexpected foes, competition is evolution's ultimate driving force. Is the secret behind the incredible diversity of life on earth, and the most extraordinary animal powers.