'Doctor Who' Season 12 Episode 8: Why did the Doctor mindwipe Ada Lovelace but let her father be?
This article contains spoilers for 'Doctor Who' Series 12 Episode 8 — 'The Haunting of Villa Diodati'
Despite the long decades that 'Doctor Who' has spent on air, there's still a lot of ambiguity surrounding the titular Time Lord's abilities and the way they choose to use them. The effect the Doctor (Jodie Whittaker) has on history is one of those highly ambiguous parts of the show.
For example, in 'Doctor Who' Series 12 Episode 2 'Spyfall Part 2', the Thirteenth Doctor wiped the minds of the historical figures Ada Lovelace (Sylvie Briggs) and Noor Inayat Khan (Aurora Marion) and fans were not at all pleased, partly because it echoed the eventual fate of Donna Noble (Catherine Tate), a fan-favorite companion who also had her memories of the Doctor erased.
Now in 'The Haunting of Villa Diodati', the Doctor interacts with a number of historical figures without a single mindwipe in sight. To make matters worse, one of the people she meets is the poet Lord Byron (played by Jacob Collins-Levy) who was Ada Lovelace's father and she actually tells him that she knew his daughter, something that even the eccentric mind of Byron must have noted as a strange occurrence.
Things get even more convoluted when the Doctor shows Percy Bysshe Shelley (Lewis Rainer) a "sneak peek" of how he would eventually die, something she actually apologizes for but never bothers erasing. Back in the Steven Moffat era and the Russell T Davies era before that, the Doctor's seemingly random choices were explained saying that there are some events that cannot be changed while others are open to interference by time travelers but even that explanation doesn't quite fit the facts that have appeared this season.
Perhaps with time, we might get a better explanation than "the writers thought it would be a great idea" but for now it seems that's all we have to fall back on.
'Doctor Who' Series 12 airs with new episodes every Sunday at 8/7c on BBC America.