The Doctor next returns to Victorian England, where he seems to run into a strange man fighting the Cybermen. The man refers to himself as the Doctor and a time lord, leading the Doctor to believe he’s met a future incarnation.
However, the man’s lapses in memory, strange use of the Doctor’s phrases and other elements lead the Doctor to suspect that this “Next Doctor” is not quite right. The Doctor soon finds out that he’s an unwitting impostor, who accidentally downloaded information from the Doctor into his brain, mixed with traumatic shock after his wife was killed by the Cybermen, and his son kidnapped to help build the “Cyberking”, a massive Cybermen designed to convert London.
The Doctor is able to, with the help of the man-Jackson Lake-to defeat the Cybermen’s planned invasion.
The Doctor’s next adventure at Easter has him boarding a bus which then is unexpectedly transported to a desolate alien world.
The Doctor teams up with Lady Christina, an art thief, to discover that the planet was consumed by alien monsters and that Earth is their next target through the transport. The Doctor is able to seal the rift after safely getting the bus passengers back home, but he is warned by a passenger that once again “his song is ending” and more cryptically, that “he will knock four times”.
The Doctor next goes to Mars in the future, where he meets the crew of a survey station, Bowie Base one. However, BB1 is important as a ‘fixed point’ in time, as it’s destruction with no survivors,would later inspire humankind to explore other worlds. The Doctor discovers the source of that destruction-the crew is being turned into strange “water zombies” via the water supply. However, he initially is reluctant to interfere and tries to walk away. However, since the time lords are no more, the Doctor is able to save some of the crew, and return them to Earth.
Having partially changed what was thought to be unchangeable history, the Doctor experiences a brief ego trip-calling himself the Time Lord victorious. However, the suicide of the ship’s captain shocks him into his normal self, and then an Ood appears in the snow, summoning him.
After hesitating for a bit, including briefly getting married to Queen Elizabeth (which will become more relevant later), the Doctor returns to the planet of the Ood.
There, they warn him of the imminent ‘end of time’-created by the Master-who at that moment is being resurrected by a cult of his followers on Earth using a combination of elixirs, the ring containing his consciousness, and Lucy Saxon’s DNA.
However, Lucy Saxon manages to sabotage the Resurrection. The Master, however, survives, although now he’s kind of messed up, with his hair turned blonde, his skin turning transparent at times, and an insatiable hunger. Plus even more crazy.
The Master is soon captured by millionaire Joshua Naismith, who wants to use the Master’s genius to repair a device known as the immortality gate, which can heal any wound and possibly make people immortal.
The Doctor teams up with Wilf-Donna’s grandfather-to track down his old enemy. Wilf has also been haunted by visions of a mysterious woman in white, who seems to have knowledge of the Doctor.
Eventually, they arrive at Naismith’s mansion, where the Master is finishing the final repairs. There they meet two alien scientists who have been hoping to recover the gate. The Doctor soon learns that the gate can operate on a planetary scale-and in the hands of the Master, that’s a bad thing.
And it definitely is, as the Master turns every human-except Donna, due to her time lord DNA absorbed from the Doctor, and Wilf who is sealed in a special chamber-into a copy of himself!
Meanwhile, elsewhere, it’s revealed that the Time Lords are alive-led by their ancient founder-Rassilon-and want to return to the universe!
Rassilon is played by former James Bond actor Timothy Dalton.
Turns out the time lords are from a point just before their destruction by the Doctor, and wish to escape that fate. They’ve managed a complex scheme-to ‘home in’ on our universe using the drumming in the Master’s head (Which they created in the first place)-which has now been duplicated a couple billion times.
The Master plans to once again conquer the universe using Earth. However, he soon learns of the time lord plot as well. The Doctor and Wilf escape to the vessel of the alien scientists, and the Doctor figures they’ve got to somehow shut the gate down and take out the Master in order to save humanity. Donna’s mind-shaken from the recent events-also starts to remember, but she passes out before it can do her harm.
Meanwhile, the time lords arrive on Earth, taking Gallifrey with them in orbit, and also undoing the Master’s spell. Turns out they want to use the massive instability to wipe out the universe and become higher consciousness gods.
The Doctor however shoots out the Immortality gate’s controls, causing Gallifrey to recede into a time lock. Rassilon attempts to kill the Doctor before he fades, but the Master intercedes, attacking Rassilon with his concentrated life force energy.
The Master, Rassilon, and Gallifrey fades into parts unknown.
Amazed that he’s survived it all, unfortunately there’s one final test. Before the fight with Rassilon, the Doctor left Wilf in the Immortality gate’s controls, which are unfortunately leaking radiation and will kill Wilf if he remains there. The Doctor decides to sacrifice himself, absorbing the radiation into his own body and saving Wilf. Unfortunately, it’s begun to eat away at his body, although he still is able to have a farewell tour to his companions.
He helps Martha and Mickey (now married) take down a Sontaran. He gives Donna a winning loterry ticket. He saves Sarah Jane’s son from being run over from a car. He salutes and helps set up Jack with a date. He even stops by a woman named Verity Newman, who is the look-alike granddaughter of his lover when he was a human, Nurse Redfern (and she’s written a book about that adventure)
Last but not least, the Doctor travels to New Year’s day 2005, where he sees Rose and Jackie prior to their first meeting, although he stays in the shadows in order to prevent a paradox. He tells her he’ll have a great year, as she’s going to meet him.
With a little help from the Ood, the Doctor staggers to the TARDIS, and begins his regeneration. He laments the loss of his tenth life: “I don’t want to go!”
The regeneration unleashes a massive amount of energy, as the Doctor has delayed it until he could say goodbye to his friends, severely damaging the TARDIS.
The regeneration changes him into a slightly younger, energetic man, with wide eyes, a big chin, messed up hair, and a tendency to yell “Geronimo” while the damaged TARDIS spins wildly out of control.
The eleventh doctor has arrived.