Tom Campbell, a London constable,
mistakes Dr. Who's time machine for an alarm box, in his haste to
report a robbery in progress; he inadvertently joins Dr. Who, his
niece Louise, and his granddaughter Susan on a journey to the year
2150 A.D. They discover that London has been desolated by
meteorites and cosmic rays and its inhabitants converted into robots
by Daleks, mechanical invaders from another planet.
While exploring the ruins, Tom and Dr.
Who are captured by Daleks, but Louise and Susan are rescued by
underground resistance fighters David, Wyler, and Dortmun.
Gallantly attacking the aliens with makeshift bombs, David helps Dr.
Who escape, but Louise and Tom are left behind inside the Dalek
spacecraft. (According to one source, Dortmun initiates the
bomb attack.) Wyler and Susan flee to the outskirts of London,
narrowly escaping an attack by Daleks, but Dortmun loses his life.
Betrayed by a family desperate for food,
Wyler and Susan are taken as prisoners to a huge mine worked by
slaves under orders from the Daleks. Here they meet Tom and
Louise, who have escaped from the spaceship, as well as David and
Dr. Who, who have learned that the Daleks are planning to blast out
the earth's metallic core with a bomb and use the planet as a giant
spaceship. At the last moment, however, Dr. Who successfully
deflects the bomb and releases a powerful magnetic force which sucks
the invaders into the core of the earth, thus restoring the planet
to its human inhabitants. The four Britons return to their own
time, and Tom single-handedly catches the robbers.