DOCTOR WHO IN DETAIL

In Bowie Base One, on Mars, things are all normal. The Captain is receiving a message from Earth, and Yuri is putting up cheap jokes. The only unusual thing is a stranger on the planet in a red space suit.

Captain Adeliade Brooke questions the stranger at gunpoint. The Doctor introduces himself; everyone else is amazed there is a new man on the base, and want to know how that is possible.

In the biodome Andy shows the first carrot grown on Mars. He takes a bite, and falls to his knees. Maggie goes to help, and sees water dripping from him. When he turns round his mouth is cracked.

The Doctor, whilst being questioned, learns he is in Earth's first off world colony, Bowie Base One, on Mars, November 21st 2059. The date is important; the Doctor knows what is going to happen, what needs to happen, and decides to leave straight away. Before he leaves Ed calls Maggie to say they should meet the Doctor, but only hear growls from the biodome. The Doctor tries to leave, but Adelaide tells the Doctor he is going no-where - except with her to investigate the biodome, along with Tarak Ital and Gadget, operated by Roman.

They find Maggie collapsed in the corridor. Tarak calls for help, and nurse Yuri and Ed go to help. The Doctor warns everyone not to touch her without gloves. The Doctor, Adelaide anmd Tarak continue to the biodome looking for Andy.

Maggie recovers in the medical bay, but she has no memory of what happened. Maggie says she feels fine, and asks Yuri to let her out. The rules say at least 24 hours. In the biodome Tarak find And, soaked in water. At the same time, Maggie is changing, and her mouth is becoming cracked. When Yuri turns round he sees water pouring from her mouth.

As the Doctor and Adelaide return to Yuri they pass Andy, who is stood over Tarak. Both are soaked in water. Adelaide and the Doctor run, chased by Andy and Tarak. They make it to an airlock as Andy and Tarak spray it with water. They manage to open the airlock, and to escape them the Doctor gives Gadget a boost with the sonic screwdriver. With this Adelaide and the Doctor can outrun Andy and Tarak.

Adelaide and the Doctor meed Ed and Yuri in the medical bay where Maggie is still pouring water. Ed reminds Adelaide that an unknown infection means Action Procedure One - evacuation of the base. Adelaide agrees, and the personnel begin evacuation procedures. There is a problem: the water is clever. Sometimes people change straight away, sometimes it hides. The personnel could already be infected, and the infection must not be allowed to reach Earth - a world full of water. Yuri shuts down the medical bay, but Maggie manages to get out, disabling the medical bay camera.

Adelaide and the Doctor look at the ice field that provides the base with water. Adelaide wants to know how the Doctor knows so much. The Doctor explains that there are moments in time that must happen - and that this is one of them. Reviewing Andy's logs they see a replacement filter was the wrong size, leading to unfiltered water. It also means the filter was changed that day, so if no-one has touched the water today they are no infected, and can go back to Earth.

The Doctor is given his spacesuit back, and he watches as the personnel start loading food for the journey back to Earth. He watches sensors as they indicate two figures (Andy and Tarak) on the roof of the control room. Everyone notices the sensors, and they can hear the ceiling creaking. The Doctor knows that this is the day the base is destroyed - killing everyone. He finally leaves them to their fate, The lift won't work, and Adelaide demands to know what happens. The Doctor tells her that on this day Captain Brooke activates Action Five - detonation of the nuclear device at the heart of the dome.

Adelaide releases the lift as water starts pouring into the control room, and covers much of the stuff being taken back to Earth. The Doctor is still listening in the lift as Steffi is caught behind a shower of water. He starts to make his way back to the TARDIS.

Ed is in the ship preparing for take off as Adelaide, Mia, Yuri and Roman make the long way round. Roman is caught by a drop of water, and starts to change. Inside the ship, Andy makes his way inside and sprays water over Ed. Ed has no choice but to destroy the ship to stop the water getting to Earth. This means there is no way for Adelaide, Mia and Yuri to get off Mars.

The Doctor is caught in the explosion, and realises he has to intervene. He returns to the control room. The Doctor had been told 'he will knock four times' before dies, and there is no-one knocking. The Doctor unpacks Gadget and, positioning the TARDIS key in it's hands, remotely drives it across the surface of Mars, as Adelaide activates Action Five. Using Gadget the Doctor is able to pilot the TARDIS into the control room.

With seconds to spare before the base explodes the TARDIS materialises.

Afterwards the TARDIS arrives in London, Earth, 21st November 2059, with Adelaide, Mia, Yuri and Gadget. Mia is in shock after seeing the inside of the TARDIS and runs off; Yuri follows her.

Adelaide realises that the Doctor has changed the future; she was supposed to die on Mars, and this could affect the motivations of her children for venturing in to space after her, altering all that the Doctor told her was going to happen. No-one should have that much power over time. The Doctor always thought he was merely a survivor of the Time War. Instead, he thinks of himself as the winner, and that the Laws of Time, that belonged to the Time Lords, now belong to him.

Adelaide returns to her house, and the Doctor sees a blue discharge from her gun...

The Doctor realises he has gone too far, and in the distance sees a vision of Ood Sigma.