Doctor: Matt Smith (Eleventh Doctor)
Companion: Karen Gillan (Amy Pond)
Ian McNeice – Churchill
Bill Paterson – Bracewell
Nina de Cosimo – Blanche
Tim Wallers – Childers
Nicholas Pegg – Dalek 1
Barnaby Edwards – Dalek 2
Nicholas Briggs – Dalek voices
Susannah Fielding – Lilian
James Albrecht – Todd
Colin Prockter – Air Raid Warden
Directed by Andrew Gunn
Written by Mark Gatiss
Script editor Brian Minchin
Produced by Peter Bennett
Executive producer(s) Steven Moffat
Incidental music composer Murray Gold
Production code 1.3
Series Series 5
Length 45 minutes
Originally broadcast 17 April 2010
The Doctor and Amy take the TARDIS to the Cabinet War Rooms during The Blitz of the Second World War, one month after Winston Churchill requested the Doctor's help in the war effort. As the Doctor arrived late, Churchill turned to the scientific advances of Professor Edwin Bracewell, including robotic devices called "Ironsides", which are recognised immediately by the Doctor as his archenemies the Daleks. The Doctor tries to understand their purpose in being on Earth at this time, but they continue to act as Bracewell's inventions, ready to serve Britain's war efforts. Angrily, the Doctor attacks the devices, shouting, "I am the Doctor and you are the Daleks!" Unbeknown to the Doctor and the humans, a Dalek ship is in orbit near the moon; upon hearing the Doctor's "testimony", the Dalek aboard uses it to activate a "Progenator Device" and alerts its comrades on Earth. The Daleks reveal their intent and turn hostile, killing several guards and exposing Bracewell as an android before transmatting to their ship. The Doctor follows in the TARDIS, leaving Amy behind for her protection.
The Doctor learns that the ship escaped destruction at the moment of the collapse of the Dalek flagship Crucible after it fell through Time by accident, leaving it nearly drained of power. The Daleks' objective is to restart the Progenator, which contains pure Dalek DNA, thus restoring their race; since these particular Daleks were created by Davros from his DNA, the Progenator could not properly accept them as "Daleks", and thus they required a testimony from their greatest enemy to activate it. The Doctor threatens to destroy the ship, including himself, before the Progenitor completes, but the Daleks fire an energy beam at London that lights up the entire city minutes before an air raid by the Luftwaffe, leaving the Doctor's allies vulnerable and creating a stalemate.
When the Progenator completes, five brand new Daleks in larger, redesigned casings emerge from the Progenator Chamber (The Scientist, the Drone, the Strategist, the Eternal and the Supreme). They disintegrate the older "inferior" models, who die willingly. At the same time, Amy convinces Churchill and Bracewell to use the technological know-how they have obtained from the Daleks to modify three Spitfires so that they can fly in space. The pilots attack and destroy the dish on the underside of the Dalek ship that was firing the energy beam, saving London before it can be destroyed by the approaching German bombers.
The battle has claimed the lives of two of the pilots, and the Doctor orders the last Spitfire pilot to continue his attack and destroy the Dalek ship, hoping to rid the universe of them forever. The Daleks retaliate by triggering the "Oblivion Continuum", the power source inside Bracewell that contains an unstable wormhole that will consume the planet if released. The Doctor, torn over defeating the Daleks or saving Earth, orders the Spitfire to stop its attack and returns to Earth. With Amy's help, the Doctor is able to convince Bracewell that he is more human than machine, deactivating the device. The Daleks, having played on the Doctor's compassion for Earth, announce their victory and retreat into hyperspace. The Doctor and Amy remove all the advanced technology borrowed from the Daleks despite Churchill wanting to use it for the war, and convince Bracewell that he need not be deactivated because he helped save the world. As they leave, the Doctor ponders why Amy does not remember the Daleks from their previous invasions of the Earth. As the TARDIS dematerialises, another crack is revealed in the wall behind it.