Fourteenth Doctor's bi-generation
Now, someone tell me what the hell is going on here?
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.
History
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 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 prize mallet in hand, the Fifteenth Doctor copied their TARDIS in two so that he could continue adventuring while the Fourteenth Doctor could retire to heal from lifetimes of loss and battle until the time he was ready to undergo a full regeneration. (TV: The Giggle [+]Loading...["The Giggle (TV story)"])
Behind he 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.
