10 Doctor Who Fan Theories That Will Blow Your Mind

In the Series 8 episode Listen, the Doctor is acting very strangely - even more so than usual. He's come to the conclusion that a mysterious race of creatures must exist, a species that has evolved to be perfect at one thing, and one thing only... hiding.

After all, there are perfect hunters, and creatures perfectly adapted to living underwater, so why couldn't there be a creature whose primary skill is to hide from view? More to the point, if such a species existed, how would we even know, given that we should never be able to see one?

While it's entirely possible that the Doctor has just gone mad from his own fears and nightmares, that doesn't explain how we actually see one of these creatures midway through the episode, when Clara, the Doctor and Rupert Pink are stood with their backs to it. It's a little blurry and hard to make out, but there's definitely something there - so what is it?

Well, prior to writing this episode, Steven Moffat had already created a species that was skilled at hiding in plain sight: the Silence, or Silents.

These bone-headed humanoids have a unique survival mechanism: as soon as you look away from them, you forget they ever existed. In theory, there could be one stood behind you right now, because each time you noticed it, you'd forget it again as soon as you tried to run away.

While the creature behind Clara, the Doctor and Rupert does look too small to be a regular Silent, there's a chance it could be a younger, shorter one. Silents prefer to be unobserved and they live to hide, so their M.O. perfectly matches the one thing we know about the creature in Listen.