Mosley tells the story of human biological creation. He brings to life surprising medical research, revealing the improbable sequence of events that lead to birth. State-of-the-art graphics follow millions of sperm on their dangerous race towards the egg, revealing the ingenious ways that a woman's body selects the best; illustrate a body begining to self-assemble; and, in a television first, show a human face coming together. The programme follows the progress of a couple who are expecting triplets, from the 4D scan when they first come face-to-face with their babies to the dramatic finale of birth. Plus, meet a woman expecting her 16th baby and the oldest conjoined twins in the world.