10 Doctor Who Details You Definitely Missed The First Time
8. A Significant Date (The Rings Of Akhaten)
The underrated Rings of Akhaten weaves together two different storylines: one set in the present revolving around The Queen of Years being sacrificed to appease a giant monster, and the other set in the past, centring around Clara's parents.
Ellie Oswald is shown to be a kind and caring mother who Clara misses very much. In the episode, we see her gravestone, which reveals that she died at the age of just 44, on 5 March 2005.
It's not something you're likely to register on that first watch of the episode, but the date of Ellie's death holds more significance than it appears. In the Doctor Who universe, that's the same date as the 2005 Auton invasion, as depicted in the very first episode of NuWho.
While it's never been confirmed, this detail heavily implies that Ellie was killed during the Autons' assault. Considering her daughter's historical connection to the Doctor, it's not an impossible idea.