Surrogacy is often seen as a frightening emotional triangle - a rare answer to childlessness fraught with ethical problems. But in Britain, at any one time, some 20 surrogate arrangements are known to be happening. Many are successful and take place in secret. Mark and Rona lost their baby and, in a fight for Rona's life, surgeons removed her womb. Thought too old to adopt, they were determined to have a child and agonized about surrogacy. This special edition of Q.E.D. follows them from the decision to go ahead until the day when the baby was handed over.