Nine takes Rose back to the day her Dad Pete died in 1987 so she can be with him when he fails to SPLINK. Except Rose fucks up and saves him, leading to a "wound in time" which summons a bunch of time-reapers who eat everyone. Rose fucks up again when she ignores the Blinovitch Limitation Effect and touches the infant version of herself, summoning a reaper who eats the Doctor.
Pete eventually figures out that to get rid of the reapers, he has to throw himself under the car that was meant to kill him.
Danny Splink later continued this proud tradition of being hit by cars in honour of Pete.
- >"Sorry Adam, I know you had good intentions, but I only take the best, I can't in good conscience take companions that abuse the laws of time for self interest."
- >"Doctor I saved my father from his fated death and summoned a horde of crappy-looking space parasites that have devoured humanity!"
- >"It's okay we all make mistakes, just tell me yer sorry."
Literally next episode, BRAVO RUSTY.
Fathers Day would later be remade as the series 6 finale The Wedding of River Song.
Heavy on the feels.