One Life tells the inspiring true story of Sir Nicholas "Nicky" Winton, whose endeavours on the eve of World War II saved more than six-hundred children from the Nazis. When visiting Prague in 1938, he sees the Jewish refugees and does what he believes is the right thing to do. War is approaching, and it's a race against time. How many can he liberate before it runs out? Fifty years later, Nicky is haunted by the fate of the children he wasn't able to help. It's not until he's surprised by the survivors on live television that he can accept that when facing devastating atrocities, saving even one life is a victory, and the British public learn the truth about the hero hidden in their midst.