
False Dawns: France falls in 1940 and Donitz's U-boats embark on a race to sink British merchant ships. Roberts' wargaming ideas are at last entertained by a desperate Admiralty. (S1, ep 2)

The Mastermind: World War II breaks out and a force of U-boats attempt to starve Britain into submission. Meanwhile, Vera Laughton Mathews recruits talented women into the Wrens. (S1, ep 1)

False Dawns: France falls in 1940 and Donitz's U-boats embark on a race to sink British merchant ships. Roberts' wargaming ideas are at last entertained by a desperate Admiralty. (S1, ep 2)

Stalemate: With the Allies at crisis point, pressure mounts on the Wrens to prove their worth and the stage is set for a battle that will turn the tide of the Atlantic war. (S1, ep 5)

Stalemate: With the Allies at crisis point, pressure mounts on the Wrens to prove their worth and the stage is set for a battle that will turn the tide of the Atlantic war. (S1, ep 5)

The End Game: The battle hits a turning point and Donitz unleashes an advanced torpedo to flip the momentum. Roberts and Laidlaw must devise a strategy to combat the new threat. (S1, ep 6)

The End Game: The battle hits a turning point and Donitz unleashes an advanced torpedo to flip the momentum. Roberts and Laidlaw must devise a strategy to combat the new threat. (S1, ep 6)