This time his hair actually turns black, and his eyes turn blue, and he opens his mouth - 

winces, realigns his jawbone with an uncomfortable crunching sound - 

- and says, "I owe you several apologies, I think." 

Meanwhile:

Basically everyone in the year who's not scheduled to be in Astronomy right now (Carter, Gadlen, the Vector twins) and doesn't have a free study period instead (Bones, Snape, Wilkes, a few others) is supposed to be in Charms. They're usually not scheduled on top of each other, but this year there's no overlap and the next best physically possible overall schedule was in all other respects worse. 

A weird number of them aren't, though: Evans, who definitely signed up for Charms and is nowhere to be found; Kovachev, who is apparently having some kind of medical problem; and Hall, who apparently was last seen making unhinged Slytherin-related choices for no discernable reason. The second two things might be related, since they're roommates, but it's sort of hard to see how.

"Good morning, good morning! This is NEWT Charms and I am so delighted to welcome all of y--" 

Flitwick stops. He leans forward from his perch on his desk, squinting. He consults his classlist. He puts on his spectacles, just to be quite sure. 

"--some... of you?" he corrects, worriedly. 

"Uh, Sasha's in bed with a migraine but he's not like dead or anything," volunteers the remaining Hufflepuff in the room, Dáithí Moran. "Daniel's probably on a friendship quest?" 

This is a common Hufflepuff phrase meaning actively engaged in trying to rescue someone from evil by the power of friendship, a thing they do all the time. 

"Lily is um. On a non friendship quest. I think." 

Did he miss her explaining this while his brain was full of exclamation points? Heck. Immediately failing at being the best boyfriend ever. Gotta work on that. 

So, the thing about trying to solve the future from the vantage point of 1981 is that you know the identities of a lot of Death Eaters,  but continue to have absolutely no earthly idea how to defeat the bloody Dark Lord. She has tried. Multiple times, even! With James right there! With Dumbledore right there! And yet! 

Accordingly Lily's priority is not, actually, killing Voldemort. 

Ninety minutes after she exits the grounds of Hogwarts, an insistent alarm goes off in the Auror Office, indicating that somebody in a registered wizarding residence with standards-compliant wards has just called for help. 

Amelia Bones squints at the map. "Am I hallucinating," she says, fascinated. 

     Alastor Moody casts a half-dozen charms on her to check, just in case. "No," he says, frowning. He doesn't really have a 'surprised' setting, just 'alarmed.' 

"Okay," says Amelia, slowly. "Well, I suppose-" 

     "Wait, wait," interrupts Emmeline Vance, "surely you are not seriously going to-" 

"Vance," she snaps, severely, which causes Emmeline to stop talking in alarmed surprise, because the Director normally addresses Auror trainees, with personal fondness, by first name. "The Auror Office does not take sides. Any wizard within the borders of the Isles who calls upon us for defensive aid is entitled to receive it." Not that this doesn't sometimes stop them from retreating to a man to Avalon and causing all parties to an unapproved war to receive no aid because there is nobody in the office at all, but they are not there, yet. 

      "....right," says Emmeline, uncomfortably, "but, Director, the Lestranges--" 

"Technically they're French," volunteers Andrew Waffling, helpfully. 

      Mad-Eye starts cackling delightedly. 

Amelia throws up her hands. "You're doing the paperwork if they sue." 

     "With any luck they won't survive to do any such thing," says Emmeline, grinning. There's quite a number of red lights blooming around the Lestrange estate on the detectors now, not only an alarm but also a fair number of illegal curses. Which means they're pulling out all the stops against whatever it is just decided it wants to wipe them off the map.

"Please don't say things like that in the office," sighs Amelia.  

     "Sorry, sorry." 

(Certainly she is not casting any illegal curses. It's all them. Where would a poor innocent Muggleborn witch have learned any of those? :) :) )

Okay. Focus. The thing that proximately went wrong is they thought Voldemort died in 1981 and this turned out in 1994, very lethally, not to be true. They've got nineteen years of lead time on the latter and about five and a half on the former. Normally the natural solution would be to warn Dumbledore that his plan didn't work so he could make a new plan, but in fact his plan was just to hold out until some sort of mysterious prophecy bullshit occurred and if he'd had any other plans on offer with literally any chance of succeeding he'd have tried them. The man can be kind of insane about divination but not that insane, he talks to Alastor ever. 

So the root cause is they fully do not understand how to kill Voldemort. 

Motherfucker, she's going to have to pretend to be a Death Eater, isn't she. It's not that she can't, she's an adult now, she can probably refrain from murdering Rosier and up til that point she was doing pretty well at it, it's just that it will suck so, so, so massively. 

She starts mentally drafting a strategy update for Lupin for whenever she gets a chance to talk to him and starts wending her way very casually over in the direction of-- who's her best-- yeah she's only got one reasonable option here. 

"Sooo how was summer camp?" Supportive wink nudge friendly-envy. 

Smirk. "Wouldn't you like to know." 

She literally would, that's why she asked. 

Bright smile. "Oh I don't want anything classified, you know me, I want gossip. Is Nott as pretty doing shield sprints as he is in a Quidditch uniform? Does Alecto still do that incredibly embarrassing giggle every time he flexes?" 

Eyeroll. "Ugh, ask Annie, am I a fashion magazine? Who cares, I can land a bloodboil hex at six hundred yards and Nott can't do it at three." 

She's a tiny baby whose counterespionage training is totally inadequate to problems less straightforward than Sirius Black and she's going to die next summer and Peggy has six dozen more important priorities. "Oh, congrats, I think my record's five seventy." 

(A bloodboil hex is not really a precision instrument compared to anything you normally aim in duelling range, but it has unusually low scattering over long ranges, so it's a battlefield standard at speeding broomstick distances.)