Doctor Who: The Timey-Wimiest Episodes Not By Steven Moffat
7. Journey To The Center Of The TARDIS (2013)
In this adventure, the TARDIS suffers severe damage when it encounters a salvage operation run by three brothers.
With Clara missing and trapped deep within the time machine, the Eleventh Doctor forces the salvagers to assist him in a rescue operation. Lost in the TARDIS, Clara is threatened by a series of horrifying and misshapen creatures—“time zombies”—seemingly born of the fiery energy at the heart of the TARDIS.
As the story continues, Clara and the Doctor discover that the zombies are actually future echoes of themselves and the salvager—indeed, they are what they will become after they are burnt and killed by the zombies. While the Doctor and Clara are able to avoid this terrible fate, the brothers are not so lucky.
Fortunately, though, the Doctor is able to reverse situation, undoing its cause, and effectively erasing the entire incident from existence.