Coral reefs are home to a quarter of all marine species. Survival in these undersea mega-cities is a challenge with many different solutions. A turtle heads to the reef's equivalent of a health spa - but she must use trickery to avoid the queue. A remarkable Grouper uses the fish equivalent of sign language to collaborate with an octopus, flushing their prey out of hiding holes. A metre-long, ferocious-jawed Bobbit Worm hides in its tunnel. Monocle Bream retaliate by squirting water to expose its sandy lair.
She experiences the rainforest for the first time travelling to the heart of the island with expert Glen Reynolds, before observing orangutans in the wild and learning how they are helping to prevent global warming. She then journeys down Borneo's Kinabatangan river and along the island's coastline to explore the unique wildlife that lives in this threatened environment.