There is an electric grid submerged deep within the Amazon River, made up of a fascinating community of fish that have technological superpowers. Biologist Will Crampton ventures into this world, one which few have ever seen, on a mission to find, catch, and study electric fish. Armed with his own electric devices, join him as he uncovers the fighting style of the jaw lockers, the navigational skills of the knifefish, and the remarkable hunting technique of the electric eel.
Marine invertebrates are some of the most bizarre and beautiful animals on the planet, and thrive in the toughest parts of the oceans. Divers swim into a shoal of predatory Humboldt squid as they emerge from the ocean depths to hunt in packs. When cuttlefish gather to mate, their bodies flash in stroboscopic colours. Time-lapse photography reveals thousands of starfish gathering under the Arctic ice to devour a seal carcass. A giant octopus commits suicide for her young. A camera follows her into a cave which she walls up, then she protects her eggs until she starves. The greatest living structures on earth, coral reefs, are created by tiny animals in some of the world's most inhospitable waters.
On the eastern coast of Africa lies a subtropical realm of staggering beauty and diversity--a mangrove forest where saltwater meets fresh and a variety of secretive forest dwellers work feverishly to survive. Take a thrilling journey into this rarest of ecosystems, one that few get to witness.