Mavic Chen and The Daleks

Some six months after the events of "Mission to the Unknown", the TARDIS materialises on the planet Kembel. The Doctor leaves the TARDIS to try and find medical aid for Steven Taylor, who became wounded in their last adventure (see "The Myth Makers"). Steven though is being tended to by the Trojan servant girl Katarina.

Also on Kembel are two Space Agents, Bret Vyon and the injured Kert Gantry who are on the planet trying to find out what happened to their agent, Marc Cory. Because Kert Gantry is slowing his colleague down, Bret Vyon leaves Kert Gantry. But no sooner has Kert Gantry gone a Dalek finds Kert Gantry and exterminates him.

Bret Vyon then spots The Doctor leaving the TARDIS, and after stealing The Doctor’s TARDIS Key and trying unsuccessfully to get the very confused Katarina to take him off the planet, Bret Vyon gives the unwell Steven some tablets. But when he again threatens Katarina, Steven briefly recovers and knocks Bret Vyon out. The Doctor then returns and ties Bret Vyon in a restraining chair before going back outside again. With Steven recovering Katarina releases Bret Vyon and they all leave the TARDIS to find The Doctor. They soon meet up with The Doctor just as the Daleks set fire to the jungle in order to drive out any further intruders.

The TARDIS Materialises on Kembel

The Doctor and his friends then witness the arrival of dignitaries from various planets arriving. This alliance has been formed by the Daleks and after infiltrating into the conference The Doctor learns of the Daleks' scheme, which hinges on the use of the fearsome Time Destructor weapon. Realising the gravity of the situation The Doctor is determined to warn the authorities on Earth. However, this undertaking proves problematic as the human leader Mavic Chen, who holds the title Guardian of the Solar System, is a traitor who is in league with the Daleks.

Fortunately, The Doctor manages to make off with the Taranium Core, that is needed to fuel the Time Destructor, thus disrupting the Daleks' plans. The Doctor, his companions and Bret Vyon are then pursued, in Mavic Chen's Spar ship, across time and space by the Daleks.

The Daleks Activate Flame Throwers

Before reaching Earth they are forced to land on a prison planet called Desperus where a convict named Kirksen manages to get on board just before they take off again. Unable to help her, Katarina finds herself held hostage in the ship's airlock. Realising that her predicament will prevent The Doctor from escaping from the Daleks, she opens the outer door and they are both ejected to their deaths in space.

In an attempt to regain the Taranium Core, Mavic Chen dispatches Space Security Service agent Sara Kingdom to track down The Doctor's party. Unaware of Chen's treachery, Sara kills Bret - her own brother - before the time travellers can convince her of Mavic Chen’s treachery. On realising the truth Sara joins forces with The Doctor and Steven.

The Daleks though are still searching for The Doctor so as to the Taranium Core and to carry out their master plan. On arriving on a newborn planet The Doctor, Steven and Sara are confronted by another old adversary of The Doctor - The Meddling Monk. It seems he has also become involved with the Daleks and in attempting to escape from them he attempts to trap The Doctor by destroying the TARDIS lock. But The Doctor is able to thwart The Meddling Monks vandalism of the TARDIS.

Bret Vyon, The Doctor, Katarina and Steven

Despite this set back the Daleks allow The Meddling Monk to carry on working for them. The TARDIS arrives in Egypt where The Meddling Monk, along with the Daleks, set another trap for our time travellers. However, The Doctor however, manages to steal the Meddling Monk's directional controller which results in The Meddling Monk materialising on an ice planet. The Meddling Monk realises that without having any control over the direction of his TARDIS he now has little chance of ever catching The Doctor.

Free at last to continue their travels The TARDIS arrives back on Kembel. There, The Doctor contrives to use the Time Destructor against the Daleks, so annihilating them. Thanks to a distraction, when the Daleks announce that their alliance is over and then kill Mavic Chen, The Doctor enters the control room and activates the Time Destructor. The Daleks return, but are powerless to do anything due to the danger of The Doctor increasing the Time Destructor's power. He orders Sara and Steven back to the TARDIS. Steven returns to the TARDIS as instructed but Sara refuses to go.

The Doctor and Sara flee with the Time Destructor through the jungle, which rapidly begins to deteriorate and die. The Daleks that are pursuing them seem to be immune to the effects. But as The Doctor and Sara reach the TARDIS they have aged massively by the Time Destructor. As the two collapse Sara disintegrates. Steven rushes outside and tries to deactivate the Destructor, but he too begins to rapidly age, he tries to help The Doctor, but is ordered to get back into the TARDIS. Fortunately, when trying to deactivate the destructor Steven managed to reverse it, thus causing the two to revert to approximately their previous ages. The pursuing Daleks try to destroy the Time Destructor with their weapons but instead cause it to run uncontrollably fast, destroying the Daleks and reducing the planet to a lifeless, barely habitable wasteland.

Some time later The Doctor and Steven emerge from the TARDIS, the Time Destructor having burnt itself out. As they look around at all the destruction that has taken place The Doctor mutters ‘What a terrible waste’. They then prepare to leave but with the recent deaths of Katarina and Sara this just leaves Steven to continue travelling with The Doctor.