When war breaks, translator Harry Chase vows to help his Polish lover Kasia flee Warsaw, but how will he explain this to his sweetheart Lois, waiting for him at home in Manchester?

December 1939, and Tom fights for his life on board the HMS Exeter at the Battle of River Plate. Meanwhile, Harry and Lois have a more personal battle to fight.

Harry’s courage is tested at Louvain as he comes face to face with a German sniper, and Kasia’s resistance activity in Warsaw intensifies.

Harry leads his unit on the route to Dunkirk as they fight to make it onto the beach and aboard a ship. Grzegorz and Tom also struggle to survive the chaos of the evacuation.

June 1940. The Nazis have taken Paris with not a bullet fired. Webster and Albert's life in the city they love will never be the same again.

On a Polish mission as part of the SOE, Harry grasps a second chance at saving Kasia from the horrors of Warsaw, while Lois looks set for happiness with new love, Vernon. Season finale.