Brian travels across the US and encounters some astonishing creatures that reveal how the senses evolved. It is a story that takes him through life's journey, from single-celled organisms to sentient beings.

Brian asks how, from a lifeless cosmos, it is possible that a planet can produce the more than eight million species we know of.

Brian explores the physics of the size of life through some close encounters with Australia's wildlife. From swimming with great white sharks to tracking red kangaroos, he discovers that the size you are profoundly affects the life you lead and, ultimately, how long you have to enjoy it.

Immerse yourself deep into the ocean in search of the most dangerous predators in our seas. Unveil the mysteries of these fascinating and skilled hunters. Razor-sharp teeth and lightning-fast reactions rule in this unforgiving environment. Are you ready to discover the facts behind the myths and legends about sharks, barracudas and moray eels? Shot in 3D, this documentary introduces you to the Kings of the Sea in an unprecedented way

Brian considers what it is about our world that makes it a home for life and asks what ingredients were necessary to transform this once barren planet into the Earth we know today? He reveals that it was a rare chain of events combined with the power of life itself that have made Earth unique amongst the cosmos.

Horizon discovers what your cat really gets up to when it leaves the cat flap. In a groundbreaking experiment, 50 cats from a village in Surrey are tagged with GPS collars and their every movement is recorded, day and night, as they hunt in our backyards and patrol the garden fences and hedgerows. Cats are fitted with specially developed cat-cams which reveal their unique view of our world. You may think you understand your pet, but their secret life is more surprising than we thought.