'How do you say thank you to someone for giving you their heart? It is the greatest gift a person can ever give.' On one side of the country, Marc is a 15-year-old promising young Scottish footballer. On the other, Martin is fun-loving 16-year-old. Both are enjoying their summers when they are suddenly struck down by debilitating illnesses. Within days the boys are close to death. Although their paths have never crossed, their fortunes are about to be bound in the most extraordinary, intimate way. One of them will die and in doing so, he will save the other's life. This is a deeply powerful and dramatic story. It is extremely rare for the family of a donor to have any contact with the recipient of their loved one's organ. Yet remarkably, the mothers of these two boys meet and become friends, enabling the extraordinary, bittersweet moment in which a mother who has lost her son meets the boy he saved. Reaching out and placing her palm flat against his chest, she feels the heart of her son beating away inside another. Her boy, the boy who gave his heart away.