Well, if no one remembers Sarah Jane aside from Maria and shifty new neighbor Andrea, how does Sarah Jane get back?
Then again, no one remembers Maria aside from her father anyway.
See, there’s a problem in the past, and that’s in 1964 where Sarah Jane and Andrea are friends. One will fall off a pier to her death and in this new timeline, that’s Sarah Jane. Maria’s warnings don’t quite work on a pair of 13 year olds, and then that short alien zaps her to a timeless void.
Timeless voids are, like, the worst voids ever.
Regardless, Sarah Jane is there. The missing adult one. See, this eyeless entity in a cowl, the Trickster, he likes chaos, and he knows Sarah Jane and Mr. Smith have to stop an extinction-level event. He’s already diverted all the other threats Sarah Jane defeated because he really wants that meteor to hit. In the original timeline, Andrea fell to her death, but in this altered timeline, the Trickster spoke to her and offered to let her live if she and Sarah Jane switched places. Being a scared 13 year old, she agreed.
Forty years later, at her birthday party, she starts to see why when a meteor is headed towards Earth.
Now, there is one hope: Maria’s father Alan was holding the puzzle box when she disappeared, so he remembers his daughter and now realizes her “Sarah Jane” talk was true and demands answers even as ex-wife Chrissie, hardly mother of the year material before, doesn’t recall Maria existed. No Luke either since Sarah Jane never adopted him. Though Clyde apparently is just hanging around at an adult’s birthday party, and that is weird.
Confronting Andrea doesn’t work for Alan because she just panics and asks for that short alien to make him go away too. Of course, taking out a sleeping older woman or a 13 year old girl is a lot different than sending some short guy to make an adult human male disappear, so it does not go well for the alien. Alan can get Maria back, but not Sarah Jane.
Sarah Jane is learning a lot about the Trickster while all this is going on. Mostly that he’s a dick, but also, he wants to do the same thing to the Doctor. That ain’t right.
Regardless, Andrea sees the meteor coming, realizes she did have a good 40 years (but no husband or kids…not that a woman needs those things, but it does make it easier to give up her own life if her children don’t cease to exist since she doesn’t have any), so she takes back the deal, Sarah Jane uses Mr. Smith to stop the meteor that was freaking everybody out, Luke returns, Clyde runs in with a “we did it!” despite the fact he didn’t actually do anything, and Alan wants to know what’s going on with the woman with the alien supercomputer in her attic.
That last part might be more problematic.