And soon, Lily receives a note.

Lils,

You know how I said I couldn't involve you in Slytherin business, after the explosion?  Well, apparently I'm doing it anyway, indirectly, if you want to help; this murder attempt has offended me and I am going to solve it and make the person who Obliviated a Ravenclaw regret their life choices.

Want to help me interrogate the portraits?  You're very charming, you know.  And...  Well, I do want to spend more time with you than I've been getting, lately, even if it's for this kind of horrible reason.

With love,

  -- Ophelia

! :D 

Lily has been VERY BRAVELY not doing ANY Gryffindor Shit(tm) about whatever is currently Up with the Slytherins even though she REALLY WANTS TO because that would be RUDE (and also dangerous, like, she understands that Ophelia is attempting Subterfuge and the heroic thing to do here is to not fuck that up for her and study hard and do warfare later) and she may possibly be literally giggling and kicking her feet upon receiving this note. 

Sirius, from an adjacent chunk of squishy scarlet couch, gives her a somewhat concerned look. He's been increasingly withdrawn and jumpy as the end of year approaches, because he's going to have to go home. He's got a quite shiny first-year exam report to show off, he actually hit top of Gryffindor despite the stiff competition(1) and relatedly tied with Ophelia for overall top of class(2), but he somehow does not expect this to entirely mollify them. He is hoping that they'll be too busy being incandescently furious about Andromeda to pay very much attention to him but this does not render him zero nervous. Mystery letter? Concerning? Alarming? What if it explodes?? What if it contains news that her parents have been horrifically murdered??? 

Okay no come on she would have noticed and anyway that was obviously a happy noise. It's fine. He can be normal. This is a normal Hogwarts occurrence.

(1) Lily and Remus got distracted in the middle of the Charms final arguing with Flitwick about an exam question that they felt was so simplified as to be on the edge of technically incorrect, with a result that both their exam reports have little Professorial Special Commendation flags on them (Lily's also has one from Slughorn for similar reasons), but their total scores are technically very slightly lower, and Sirius will simply not be explaining this context note to his parents 

(2) The Ravenclaws would be more salty about this if it had been anybody else, but Ophelia has 'excused from any and all Ravenclaw ire for minimum eighteen months' privileges courtesy of the Vectors, and it's kind of Known at Hogwarts that the House of Black is exempt from normal standards, losing to them basically doesn't count 

Therefore: "Eh? Letter from your girlfriend?" he says, with at least 70% of his usual cheery friendly-banter smile. This approach to discussion of Lily's favorite Slytherin is a little bit for politics reasons, they had a talk at one point about treading the line on pushing the social envelope on the House rivalry without causing one million drama, but also you just gotta make fun of your friends for having crushes when you're twelve, it's the rules.

"Shut uuuuup," slightly blushy fond arm-punch as she rereads for details instead of doing a quick initial skim and mostly catching charming and regret their life choices and love. "--ooof, apparently somebody Obliviated Nelya Vector, yikes? Anyway I am being invited on a quest." This is a noun that it is understood among Gryffindors you do not turn down even if it comes from a lightly concerning source because obviously. 

Remus is sitting on the other side of Sirius playing Snap with Peter. (They're about evenly matched at this when Remus is a few days out from having been ill, which is friendship enrichment for both of them.) 

"...the kind where you want backup or the opposite of that?"

Having friends is so good. "Second one, thanks though!"

Sure, meet you by the library in a few 💖

(She can make her quill draw little hearts that actually sparkle now! This is a very useful foundational charms skill according to Flitwick, who may possibly have some ulterior motives regarding the infinite font of joyous whimsical delight that is regularly receiving student essays which contain handwritten animated emojis but is also correct.) 

Off she goes, humming. 

And she is there!  And smiling fondly at the sparkly heart.  Well, she's not looking at it - okay she might actually keep a little scrapbook of all the hearts that Lily's ever sent her but sssh and anyway it isn't in evidence now - but she's smiling fondly about it anyway.

Beam. "Hello hello! Tell me all about your quest-- er, or I guess all of it that isn't a Secret part of the quest or anything."

(Lily is somewhat naturally inclined to both the classical Gryffindor failure mode 'why would you want to do a Subtlety when you could do a Large Explosion' and also the classically Ravenclaw failure mode 'but surely, if we simply say enough true facts in a row, everyone will understand each other perfectly and it will not be necessary to do politics', but she's been observing her Defense professor set a great example on the degree to which you can simply not ever think about Slytherin shit if you really, really trust your Slytherin to only ever do Good secrets and not Evil secrets.) 

"What are we asking the portraits?" 

"Who was out on the Quidditch pitch at the same time as Nelya Vector was, on the evening of the explosion.  And whether she was out there at all, but I highly suspect that the facts we have do not make sense if she wasn't out there.  The wards should have noticed, so the only solution is that she was not within the wards, or somehow maneuvered into an exception within them that I cannot believe I would not have heard about at this point."

"Huh. Do the portraits pay attention to that. I guess we probably want to talk to, hmm-- oh, I know! Violet!" 

She hangs in the antechamber by the Great Hall where the big doors to outside are, is great friends with Gryffindor's Fat Lady, and loves to gossip.

Thataway with them. 

As they walk: "What if it's like a lot of people, the Quidditch people are aaaaalways out there throwing things at each other." She would be more mad about first-years not being allowed to play if you could hex people in Quidditch but apparently that's like Super not allowed and this limits her interest in the sport. "Anything that'd be extra suspicious to look for?" 

"I am only concerning myself with sixth and seventh years, for now.  As for suspicious behavior...

"I don't think there necessarily is such a thing in the general case, and I've no idea how much view of the pitch the portraits even get - which would be where I suspect the majority of behavior that could be reasonably considered suspect, to have occurred.

"If they were only out there while Nelya was out there...

"But I don't think they'd be that stupid."

"You never know, Slytherins can be really stupid. Present company excepted of course. Which is good because I'm pretty sure none of the portraits can see the pitch, like, at all."

"Can they see the exits?  That's all we need to establish who could have been there, assuming...  Which, actually, we probably should not...  That there are no secret passages onto the grounds.  Ugh, that's another mess."

"It's probably better we don't assume that's pointless to determine, though.  The suspect in question may have figured out the Quidditch pitch as their best place to stake out a target, but they haven't been necessarily tracking anyone, or they'd have noticed me - which means, I think, that we can assume they would not have expected someone to be trying to track their location."

But surely, the Hogwarts Castle, a trustworthy friend, would never, let someone, secretly, go outside, if they intended to do a crime,, 

(hello hi I love you I do of course try not to do that but unfortunately I am a building, and not a mindreader,) 

"....hm. Well they can at least see the not-secret exits, yeah." 

She does have 'ask the castle if the castle saw anything' as her other option.  She'll probably try it later, if a Clue does not jump down her throat.  "...In other news, the way wands think, insofar as they do, is really...  Quite something."

She pulls a muffling effect over their conversation.

"...Lily.  I just realized.

"I can sort of ask wands things.  Because I was able to explain to Nelya's wand what I was looking for.  And wands are - kind of atemporal.

"I have no idea what the practical use of this knowledge is, but after our wand fitting went the way it did...  I kind of really want to ask if they know anything about what's up with all the other weirdness.  Like the extra boat."