Young London banker Sir Nicholas "Nicky" Winton (Johnny Flynn), on the eve of World War II, saved 669 children from the Nazis — more than the number of children who survived the Holocaust in Czechoslovakia.

With war fast approaching, Nicky visits a recently annexed Prague and witnesses first-hand Jewish refugee families with little to no shelter and food. He immediately realizes it's a race against time. How many children can he and his friends rescue before time runs out?

Fifty years later, it's 1988 and Nicky (Anthony Hopkins) is haunted by the fate of the children he wasn't able to bring to safety in England. It's not until a live television show That's Life surprises him with the surviving children, now adults, seated all around him that he can finally make peace with the tragic loss he had carried for five decades.