10 Doctor Who Fan Theories That Became Fact

Another constant element of Moffat-era fan debate was the mystery of River Song.

There were so many puzzles surrounding River – her true identity, the identity of the man she killed, the full extent of her relationship with the Doctor – and while some of these answers were more obvious than others (it was clear she’d killed the Doctor and it was also pretty obvious that they were husband and wife), theories about River’s true identity were the gift that kept on giving.

For every “She’s the Rani!” or “She’s an incarnation of the Doctor!”, there were dozens of fans predicting that River would be related to Amy Pond somehow, largely due to both of their water-themed names, but also because River’s complex timeline would have plenty of wiggle room for a connection with someone much younger than she was.

Whether this was always the plan or whether Steven Moffat saw those fan theories early on and liked the sound of them, it soon transpired that the Amy Pond connection theory was bang on the money. In a spine-tingling scene, the closing moments of A Good Man Goes to War confirmed River as Amy and Rory’s daughter, an idea that had gained greater weight in the weeks prior due to Amy’s pregnancy storyline.

The speculation that River was secretly a personification of the TARDIS though? Yeah... that didn't age quite so well.