The Time Lords alert the Third Doctor to a time rift sweeping across the galaxy, and he uses the TARDIS intuition circuits to direct him to a time when he will be able to stop it. The TARDIS materialises on Alrakis, where the Doctor and Jo are separated during one of the timestorms which have been devastating the native civilisation, the Tonska. Jo is kidnapped by rebels who believe that the Time Lords are responsible for the disaster; she manages to convince them that she and the Doctor are here to help, but they reveal that they’re driving an armoured vehicle with a nuclear bomb into the palace of the tyrant Yed-Prior Zaniah. The Doctor makes his own way to Zaniah’s palace, where he learns that she intends to channel and control the Time distortion to let her people live out natural life spans within hours while extending her own; thus, she will rule the planet for generations. The Doctor is forced to help her researchers, but discovers that their experiments to contain the Time distortion and use it to manipulate living creatures’ morphic signatures have summoned the Cerunnos, a metamorphic creature from the darkest corners of Time. Jo helps the rebels to break into the palace as the Cerunnos breaks free, but she and the Doctor can do nothing but retreat as the rebels’ bomb goes off. The force of the explosion propels the Doctor and Jo thousands of years into the future, where they find that the grim civilisation they visited has fallen long ago. But the Cerunnos has survived the explosion and fled into the Time Vortex, following the trail of the TARDIS back to Earth.
to be added
- The Cerunnos is monster spoken of in myths of planets across the universe, and which is believed to have existed in the Dawn Time. The Tonska inadvertently call forth the Cerunnos by exposing a volunteer to the energies of the time rift. The Cerunnos is parasitic and can assume any form. The Doctor considers it madness made flesh; it is implied that it is more a force of nature than an actual living, thinking being.
- Jo considers her copy of the TARDIS key to be the most sincere symbol of the Doctor's trust that he has ever given her.
- The Doctor drinks wine with the Yed-Prior.
- Alrakis orbits the star Iota Ophiuchi. The planet has a single huge moon, the orbit of which is gradually decaying and which will eventually crash into the planet. The dominant species is the Tonska, a humanoid race whose technological abilities have outstripped their ability to care for their world. The Doctor describes them as having become grey and mechanical, just like their machines. They know of the Time Lords. The highest authority on Alrakis is the Yed-Prior (which means the Foremost), who is effectively their ruler. Thousands of years in their future, after the Cerunnos is unleashed, the Doctor and Jo see Alrakis restored to a lush and verdant paradise, all trace of the Tonska long since vanished.
- Jo passed domestic science at school, rather than actual science. (TV: Terror of the Autons)
- The TARDIS is apparently operational independent of the Time Lords, setting this story after The Three Doctors.