1917. It's the height of the Great War and Hellcombe Hall is a house full of mystery: locked doors, forbidden rooms, dustsheets covering guilty secrets, and ghostly noises frightening the servants. Most mysterious of all, the drawing room seems to open directly onto a muddy, corpse-filled trench on the Western Front...

Arriving at this stately home, the Doctor meets Lord Hellcombe, an armaments manufacturer who has a new secret weapon he believes will win the war: he calls it 'the Dalek'. Soon, the Doctor and his new friends are in a race against time to prevent the entire Western Front from becoming part of the Dalek Project!