Somewhere out there, in the far, distant multiverse, is an alternative timeline where Jenna Coleman didn't make her Doctor Who debut as companion Clara Oswald, but as Melody Pond in the 2011 episode Let's Kill Hitler. That's right - Jenna Coleman was nearly an incarnation of River Song. 

The actress dropped the revelation at Canada's FanExpo convention, where she was appearing on a special panel alongside former companion Karen Gillan - AKA, Amy Pond. Following a fan question regarding Melody (what life would have been like for her if she wasn't abducted at Demon's Run), Coleman sprung to life, her memory obviously jolted:

"I've got good gossip! Did you know... that I auditioned for Mels? That's one part I didn't get and my grandmother was so upset..."

"Thank god you didn't get that!" replies Gillan, "because then you would have..." She trails off, interrupted, but it's probably not a stretch to assume that she going to say something about her then not being able to land the bigger role of Clara Oswald. Not that a past appearance in Doctor Who hurt Gillan's chances, of course. Or Peter Capaldi's.

Mels went on to be played by Nina Toussaint-White. It was a brief role: a younger incarnation of River Song who had become childhood friends with the Ponds, her parents. Timey-wimey, and so on. Early on in Let's Kill Hitler, after forcing the Doctor to travel back to 1938 Berlin, she regenerates into the real deal. 

Coleman goes on to say that she never had much faith in ever landing the role - mainly because of her and Gillan's imbalance of height. 

"I never thought they would have cast us as childhood best mates because the height difference was too much," she laughs. "I thought, 'I'm never going to get that part.'"

Funny how things work out, eh? 

Jenna Coleman, of course, will reprise Clara Oswald for Doctor Who series 9, which returns to BBC1 on 19th September - join our countdown fun here

Get your tickets to see Peter Capaldi and Steven Moffat LIVE at the Radio Times Festival at Hampton Court in London on Friday 25th September