The TARDIS loses its integrity and breaks apart into many pieces, stranding the Doctor, Tegan and Turlough in the far future on the remote planet of Frontios. They find a small group of humans apparently, the only survivors of the human race barely surviving after the crash of their spacecraft. They are under constant bombardment by meteors, and some of them have mysteriously disappeared. Turlough and Norna, a young female survivor, stumble across an underground cave system and start exploring it. Norna disappears and Turlough is found wandering around in a state of shock. The Doctor must try to make sense of Turlough’s ramblings, and discover what is happening to the survivors and can he repair the TARDIS?
As a strange force takes hold of the TARDIS, the Doctor and his
companions find themselves grounded in the inhospitable planet of
Frontios. They find the last survivors of the human race scratching out
a desperate existence far away from their long dead homeworld.
The Doctor, still trying to come to terms with the loss of the TARDIS, is
surrounded by an impromptu firing squad of Orderlies. Norna stands in
the line of fire, pointing out that even if the Doctor is an invader he will
at least know why the colony is under attack. But the Doctor needs to
come up with answers, and quickly!
Tegan manages to distract the Tractators and breaks their grip on the
Doctor and Norna. Tegan helps Norna flee to safety while the Doctor
keeps the Tractators occupied, but when she returns to help, the
gravity beam traps them both.
The Gravis seems to know the Doctor by reputation, and is intrigued
when Tegan inadvertently reveals that they travelled to Frontios by
TARDIS. As the Tractators have been marooned on Frontios for
centuries, the Gravis is obsessed with any means of travel