How does life begin? What drives a newly fertilised egg to keep dividing and growing until it becomes 40 trillion cells, a greater number than stars in the galaxy? How do these cells know how to make a human, from lips to heart to toes? How does your body build itself? Magdalena Zernicka-Goetz was pregnant at 42 when a routine genetic test came back with that dreaded word: abnormal. 25% of sampled cells contained abnormalities and she was warned her baby had an increased risk of being miscarried or born with birth defects. Six months later she gave birth to a healthy baby boy and her research on mice embryos went on to prove that the embryo has an amazing and previously unknown ability to correct abnormal cells at an early stage of its development. This book will take you inside the world of life just as it begins and reveal the wonder of the earliest and most profound moments in how we become human.