10 Doctor Who Side Characters With Tragic Backstories

10. Ada Gillyflower

The scars on Ada Gillyflower's face make it clear that her past is riddled with trauma, but even so, she hasn't let her horrific backstory consume her.

As evidenced by the fact that she voluntarily takes care of a severely injured Eleventh Doctor, she's a kind, gentle soul who was simply dealt a rough hand in life - and in her case, that rough hand manifested in the form of her mother, Winifred Gillyflower.

Early on in Series 7's The Crimson Horror, we're told that Ada's blindness and scarring was caused by her father in a drunken rage, but this is a total lie. The truth is - unbelievably - even darker still.

It was actually Ada's mother who scarred her, during a series of experiments involving red leech venom. Winifred was trying to find an anti-toxin to combat this venom, and she used Ada as her test subject throughout this process. She blinded her own daughter, for nothing more than personal gain.

What makes this even worse is that Winifred doesn't seem remotely sorry for her actions, which is why it's extremely satisfying when she falls to her death at the end of the episode. Karma at its finest.