Fifty-Fifty (unproduced audio story)

Fifty-Fifty or 50/50 was an unproduced audio story planned by Steven Hall for Doctor Who's 50th anniversary in 2013. It would have depicted a "big, epic and pretty brutal showdown" between the Seventh and Eighth Doctors, with Ace, Hex, and Lucie being forced to choose sides.

50/50 would have relied on a very different ending to the Black and White trilogy: the revelation that the Old Gods and other monsters were returning because something travelling very fast was smashing holes through the dimensions. This object would have been revealed to be the bruised and battered Eighth Doctor, who would tell Hex that the Seventh Doctor had caused it and that they were fast approaching "the moment where 7 went bad."

The story would have involved the "Temporal Wish", which could be used three times to "recalculate" time so specific events could be rewritten without timeline damage. The Temporal Wish and other dangerous technologies would have been on a ship called the Pelican headed for the Big Bang.

As Hall was planning Fifty-Fifty when he wrote A Death in the Family, many character moments there were designed to build toward the showdown between the two Doctors. However, because of the characters involved and the actors the story needed, it was deemed too expensive and never produced. Hall suggested it might fit in with a "new generation" of The Lost Stories.