Exploring the wonders of the human body. Using state-of-the-art graphics and the latest scientific research, Michael Mosley takes us on a voyage through the workings of our own inner universe. Michael tells the story of human biological creation. He brings to life medical research, revealing the sequence of events that led to human birth.

Michael Mosley shows how existence is a struggle and how, minute by minute, from your first breath to your last, your body performs countless small miracles to keep you alive. It starts with a dramatic water birth, shot in slow motion, before a stunning graphics sequence takes us on a breathtaking journey into the heart.

Michael Mosley traces our development from birth to adulthood, and reveals that the human brain is so sophisticated it takes more than 20 years to mature. We see how new-born Phoebe makes sense of the world, and how one-year-old Angelina copes with just half a functioning brain. We also discover how Moken sea Gypsy children train themselves to see clearly underwater.

In this final episode, Michael Mosley reveals the ingenious ways in which the body defends itself against a hostile world - where sunlight shatters DNA and every breath contains microbes that can kill. He meets Cristian, a bull jumper whose muscles give him the strength to avoid a violent death and three-year-old Rowan whose internal army fights off the flu virus.