This episode looks at the cognitive abilities of dolphins. We have long wondered if the universe harbours other intelligent life, but perhaps we should be looking at our own oceans. Dolphins have large brains, and are quick to learn new tricks. Like children, they also enjoy playing games.

This final episode looks at the vocalization of whales and dolphins, and how they communicate with each other.

The first episode focuses on humpback whales and blue whales - exploring the intimate details of the largest animals that have ever lived on our planet- the great whales.