The Doctor's face glows, and he begins to change… A new, younger Doctor stands up. He checks himself out in a mirror, and is pleased. "Cute, sexy and lick-the-mirror handsome." He licks the mirror.
The new Doctor is confident, self-assured, almost arrogant. He turns to the Master, and vaguely recognises him as "the camp one". The Master protests that he is not camp. The Doctor is unimpressed, but compliments the Master on his "nice tits". Again, the Master corrects him: they are bumps.
The Doctor recognises the Daleks, and his fiancée, Emma, the only time-travelling he has ever "had". He wonders whether she can still love him in his new body, but she doesn't see a problem. They run to the TARDIS which, improbably, is in the corner of the bridge of the Dalek ship.
The Daleks shout that the Zectronic beam controller is going to explode, and offer to spare the Doctor's life if he will help them. The Doctor, still intent on retiring, sees saving these "metal gits" as a good place to end his career. He tells Emma to pop into the TARDIS for a bottle of good champagne, which they can drink to celebrate the beginning of their new life together.
Emma enters the TARDIS. The Doctor thinks that, in this new body, he is going to be particulary good at rewiring. He goes to the beam controller, reaches round the back of the console, when there is an explosion…
A new Doctor staggers out from behind the console, and curses. Emma returns with the champagne, and is confused. The new Doctor, older, less confident, recognises Emma as his fiancée, and runs from her. He explains that he seems to be a little shy of girls now. Changing personas can be very unpredictable.
While Emma pleads with the Doctor to look at her, the Master emerges. The Doctor takes him for another girl. The Master, getting cross, says that he is not a girl and tries again to explain the nature of the two Dalek bumps on his chest.
At Emma's prompting, the Doctor turns his attention to the Zectronic beam controller. He decides that the problem is probably located elsewhere, and heads off down the corridor and around a corner. There is another explosion…
A new, younger, somewhat foppish Doctor staggers out from around the corner. He bemoans the fact that he has used up three incarnations in just under a minute, and all because he forgot to unplug the beam controller first. He unplugs it.
Just as he and Emma recognise one another, he is struck from behind by a beam of Zectronic energy. He falls down by the TARDIS. As Emma crouches over him, he explains that he forgot about the residual energy from the beam controller.
Magnanimously, the Black Dalek decrees that the Doctor's life should be spared, as he has saved the Daleks from destruction. The Master kneels down beside the Doctor, saying that even a Time Lord cannot survive a blast of pure Zectronic energy.
Emma had assumed that the Doctor would simply regenerate, but the Doctor says that the blast has destroyed my ability to regenerate. He asks Emma to look after the universe in his absence, but she doesn't know how they can. He starts to say that he will explain later… but goes limp.
Emma tells the Doctor that he cannot die, as he is too nice and brave and kind and silly. She loves him very much, and everyone needs him. The Master lauds the Doctor as the best and bravest of all his foes. He renounces evil and undertakes to follow the path of goodness to honour the Doctor. The Black Dalek says that the Daleks will also honour their mortal enemy.
The Master leads Emma away, but behind them the Doctor's face glows and begins to change…
A new, more feminine Doctor stands up… The Doctor notes that she has atheric beam locators, but Emma points out that they are actual breasts, and that the Doctor has come back as a woman. The Doctor wonders whether they will both wear white at the wedding, but Emma notes sadly that the Doctor is just not the man she fell in love with.
The Doctor plans to resume adventuring across space and time, fighting monsters and saving planets, with her best friend by her side, her trusty old TARDIS and her sonic screwdriver. The Doctor switches the screwdriver on and notes, possibly for the first time, that the vibrating object has three settings. Emma, disgusted, grabs the screwdriver from the Doctor.
The Master tells the Doctor that she is rather gorgeous. The Doctor thnks that the Master is a great deal more attractive than she remembers. The Doctor asks him why he is called the Master. The Master says he will explain later.
The two Time Lords walk off down the corridor, arm in arm.