8 Doctor Who Fan Theories That Became Fact

Heaven Sent is one of those episodes that leaves audiences with just the right amount of ambiguity - most of it revolving around the Doctor's confession dial, and how exactly it works.

In the episode, the Twelfth Doctor is trapped inside said confession dial, caught in a loop, dying over and over and over again, and "respawning" after each death. It's a fascinating plot device, but something that isn't made clear is whether or not the "real" Doctor was the first one to die, making every subsequent version of him nothing more than a clone of the original.

Ever since the episode aired back in 2015, many fans have theorised that this is the case, and that, after Heaven Sent, the Twelfth Doctor was actually a copy. And so, when writer Steven Moffat joined Twitter for a watch-along of the episode, this topic was bound to come up, and sure enough, it did.

In response, Moffat pretty much confirmed the clone theory by referring back to a similar event from a 1964 William Hartnell serial:

“He first teleported in [First Doctor serial] The Keys of Marinus - he’s been a copy since then - deal with it, kid."

You could also argue that the Doctor becomes a "copy" each time they regenerate into a new body - after all, the process does completely rewrite their physical form!