"Well, unless this is a stable timeloop, this is pretty unlikely to be true timetravel. I'm unsure if you'd consider multiple universes 'weirder.'"

"Stable loops are the only possible ones, Gleisse's Second Law. But thirty years is past the mathematical singularity, so Gleisse's Laws don't necessarily apply. And the Lily Evans of my past would not have let things play out the way they did if she knew about it in advance."

"You could have been planning to Obliviate me," she points out. "Since I'm apparently your mother, the lack of an impact on your timeline from this means the loop question can't be solved by my death - and quite frankly Gleisse's reasoning in the Second Law is full of shit. The core argument that unstable timeloops are impossible is that they would by their nature destroy the universe, and any timeloop occurring past the point of the mathematical singularity would be inherently unstable; that's merely an argument that they haven't happened yet."

Damn, she was hoping to gloss over the 'mum' bit.

"Obliviating you would be the responsible thing to do," Ellie acknowledges. "But I don't care much for the spell. Anyway, saying that 'impossible' is not the same as 'hasn't happened yet' is a distinction without a difference when the phenomenon in question would destroy the universe. If you did instantiate an unstable loop, no one would be around to appreciate your hard work after the fact. And consider the context in which Gleisse was writing; if they framed it your way and the Witch of Weltenburg heard that version of the theory, Bavaria would have had a bigger problem than a decade of flat beers and rivers flowing backwards."

"It's a reason to exercise caution and go slowly," she points out, "If you're messing with things on this scale anyways. Plus, that's also a reason not to publish certain works widely." 

(This might be illuminating as to why Ellie has found absolutely zero documentation of whatever the fuck Lily did when Voldemort came for her. Even Dumbledore's best reasoning after the fact doesn't quite match Ellie's actual experiences.)

"Yeah, that sounds about right for you."

"You got to know me even with my death?"

"You left some journals behind but- it was more in the shape of what was left out."

"...That does sound like me, especially with Vol-dick and his asshead supporters in the mix."

"Don't think they ever found anything of yours, so there's that."

"I'm not risking notes."

"Though that habit was a little inconvenient for me personally, when I was trying to work out what the limits of what you'd done were."

"Sorry."

"Well, it didn't prove critical, in the end."

Nod. "Would've been dumb for me to set things up so they'd only go right if you figured everything out."

"That, I'll thank you for."

Tiny smug smile. "Though I'll be disappointed in myself if I don't do better this time around."

"You'll have more help," she says. "Since I'm here."

"Good."

"Though I would prefer to work more directly, I think."

"It'd be better to not let things go another five years."

"We should start with the horcruxes. There should be at least one in Hogwarts."

"What are they?"

"The diadem of Ravenclaw, the cup of Hufflepuff, the locket of Slytherin. The ring of the Gaunts. A diary he had when he was at school. His snake familiar."

"Which one do you think is in Hogwarts?"