In the last part of this epic series, Michael Mosley charts the final months of life in the womb when cartilage hardens to form the skeleton. We meet Janelly, who was born with no bones and who only survived thanks to an experimental drug. The brain is developing rapidly too. 100 billion new connections each day are laying the foundations for memory. We meet memory man Joey, whose brain is incapable of forgetting anything he has experienced, which leads Michael to investigate exactly when our earliest memories are formed. Memories are created by what we experience through the senses and these too mature in these final weeks, though on the island of Pingelap, the sight of one in ten develops differently. These islanders are born profoundly colour-blind, which has given them a wonderful advantage in life. Finally, we witness the critical moment of the first breath and the beginning of a new life.