Fourteenth Doctor's bi-generation
Despite their belief of such a thing being a myth, the Fourteenth Doctor underwent a bi-generation, in which he was split into two versions; himself and the Fifteenth Doctor.
The Doctor's previous regeneration, going from the Thirteenth Doctor to the Fourteenth, had been only about 15 hours earlier. (PROSE: The Giggle [+]Loading...["The Giggle (novelisation)"])
History
A day to come
When Time "reunified" the Thirteenth Doctor into a singular body after she had been split into three, Time taunted the Doctor by asking "for how long" she would remain "unified". (TV: The Vanquishers [+]Loading...["The Vanquishers (TV story)"])
Cause
Whilst confronting the Toymaker, the Fourteenth Doctor challenged him to a game, the third they had played overall. However, as both of their games up to that point had been played by different incarnations, the first game by the First Doctor, and their second by the Fourteenth Doctor, the Toymaker declared that the next game must be played by the next Doctor and shot him through the chest with a galvanic beam, causing him to seemingly regenerate.
Two Doctors
However, instead of changing his appearance as usual, the Fourteenth Doctor recognised that something was different and asked Donna Noble and Melanie Bush to pull on his arms, causing him to begin to separate into two distinct incarnations, to the confusion of all present. The two Doctors greeted each other excitedly before pushing against each other to complete their separation.
Aftermath
Now separated, both Doctors challenged the Toymaker to their final game, which they won, with the Fourteenth Doctor banishing the Toymaker from existence as his reward. With a mallet in hand, the Fifteenth Doctor claimed his reward too by splitting their TARDIS in two, so that he could continue adventuring while the Fourteenth Doctor could remain behind on Earth to undergo rehabilitation, and heal from lifetimes of trauma, with the Noble family. (TV: The Giggle [+]Loading...["The Giggle (TV story)"])
The Fourteenth Doctor was not sure what lay ahead for him in the future, but wondered if one day he would fade from existence, with his future already secure in his successor. (PROSE: The Giggle [+]Loading...["The Giggle (novelisation)"])
After encountering Maestro, the Fifteenth Doctor would go on to describe the process of bi-generation as having “torn his soul in half,” and feared that he would be unable to survive another. (TV: The Devil's Chord [+]Loading...["The Devil's Chord (TV story)"])
Behind the scenes
Prior to the airing of The Giggle, the images of both the newly bigenerated Fifteenth Doctor, first seen in the trailer following The Power of the Doctor [+]Loading...["The Power of the Doctor (TV story)"], and the Fourteenth Doctor preparing to "regenerate", as seen in the trailer following Wild Blue Yonder [+]Loading...["Wild Blue Yonder (TV story)"], were modified to remove the appearance of UNIT HQ.
