The TARDIS has brought the Doctor, Jamie and Zoe to Normandy in France, not in 1066 as intended, but in 1944, three days before the Allies are due to launch the D-Day landings.

Joining forces with French partisans, they learn that the Germans have been conducting secret experiments at a nearby chateau. These experiments form part of a plan that German high command believe will enable them to win the Second World War. The name of that plan? Operation Werewolf.