How do you stay calm when you're operating on the heart of a newborn whose life is hanging by a thread that is hardly visible in your hand, but you have to tie off precisely? What do you say to a little girl facing death after her cancer invaded her heart? How do you feel when you've saved a child from death? Or lost the battle for another? Meet Swiss pediatric heart surgeon René Prêtre, who has had to face all of those questions in his career.
