Lupin was grumbling under his breath. It was a good job that none of the students had come across him whilst he walked along the corridors of Hogwarts, because they would have seen a side to him that was normally reserved for when the moon was making itself known. The pupils viewed him as a good natured man, a kind person who sought out order in his classroom through knowing what he was talking about, rather than raising his voice. Their opinions would surely have changed if they'd happened to get in his way at that very moment.

He'd walked all the way to the Quidditch grounds, which was a surprisingly long distance to cover. That was made all the more apparent when you couldn't apparate to said location. But he'd put in the hard graft, believing that the end goal would be worth it. Only for him to sit in the stands on his own. He'd expected Sirius to be there waiting for him. When that hadn't been the case, he opted to think that his old friend would show up at any moment as part of whatever surprise he was planning.

No such luck.

Which was why Lupin was now storming back to his classroom, looking to get the answers he felt he was owed. Walking through the door, he realised that he was still clutching the stupid flower Hermione had handed him and he threw it to the ground in disgruntlement. He wasn't the sort of person who typically allowed himself to be dictated by emotions, which was why he felt particularly hurt after he'd opened himself up to the possibility of something happening in the Quidditch stadium.

He was currently under the impression that he'd been the victim of some sort of prank, of the like Sirius had pulled plenty of during their time as students at Hogwarts. What the punchline of the prank was, Lupin didn't know. Was it just to make him walk there and back? If so, was Sirius just interested in his intake of daily exercise? Because there was nothing in his office that suggested it had been tampered with, meaning the only other potential outcome of the brief trip away could be crossed off the list as well.

His first port of call was to head for the fireplace, looking to go directly to the source of the fun and games. He threw the Floo powder with more force than was strictly necessary, as if that would abate some of his anger before the inevitable confrontation. Because being fuelled by such fiery passion was precisely the sort of demeanour that was a recipe for disaster, a potent mix of emotions that was likely to make him say something he really didn't want to admit to.

Much to Lupin's surprise, Sirius was quick to respond to his summons. His bearded face appeared in the embers in a way that should have been unsettling, if Lupin hadn't seen it numerous times over the years. The professor folded his arms, waiting for a response that didn't seem to be forthcoming, judging by the way Sirius' eyebrows (represented by two, small pieces of coal) came together in apparent confusion.

"Well?" Lupin began. "Where the hell are you?"

Sirius took his time before responding. "Did we…plan something that I've forgotten about? If so, I can only apologise."

"What are you playing at?"

If Sirius' fiery form had had hands, he would have raised them in innocence. "I can safely say that I don't know what you're talking about."

"You invited me to the Quidditch stadium! You planned a picnic for the two of us! I thought…I thought you were finally getting your head out of your arse and acting on your feelings!"

"Pardon?"

"Oh, but you can't resist playing the fool, can you? I should have seen this coming, frankly. It's my fault for believing you could be more mature than usual. It's on me for getting my hopes up. I've learnt my lesson."

"Can you pause for a moment and explain to me what's going on?"

"So you can make me look even more of a fool? Is someone going to jump out at me at some point and throw a pie in my face?"

Sirius chuckled, though it sounded to be born out of an uncomfortableness rather than any sort of humour. "Have you taken a dodgy potion without telling me? Do I need to summon Pomfrey? Because I refuse to ask Snape for any sort of favour. He'd probably use it as an opportunity to poison you even more."

"You hurt me, Sirius, and now you're laughing in my face."

That seemed to be enough to sober his friend up. "Okay, I'm officially concerned. What have I done wrong?"

"Did you or did you not invite me to some sort of meal this afternoon? Under the illusion that something important was going to be spoken about."

"I did not."

"You…didn't?"

"No…and that's why you'll forgive me for being so confused. I don't remember asking you to meet up. I feel as if I'd have to be involved for that to happen."

"But…Hermione came to my door. She was holding a rose and…told me to meet you. She was pretty insistent, now that I think about it."

"Hermione?"

"Do you know many of them?"

"Why on Earth would she send you off some wild goose chase?"

"Why else would a teenager sneak around an authority figure?"

"Because they want that authority figure out of the way…" Sirius' face fell. "Was Harry with her?"

"No. It was just her on her own. I thought it was strange at the time. And, the more I think about it, the more I distinctly remember Hermione being quite nervous."

"Nervous?"
"Will you stop repeating what I say?"

"Sorry! I can't help it! I'm starting to panic!"

"There's no need to worry just yet. They could be playing a prank themselves. Maybe you annoyed them and they're looking for revenge."

"Why does it have to be who's annoyed them?"

"I'm working with the law of averages."

"There's every chance that they're playing matchmaker."

"Matchmaker?"

"Who's copying who now, huh? They'll have gotten it into their heads that we need a gentle push to discuss what's happening between us. Really, I didn't think they'd picked up on anything."

"Is there something to discuss?"

Sirius glared at him, which was made more imposing by his flaming features. "We're not going to get roped into their games. We'll do it on our terms, after we've found those little pipsqueaks. So they think they can mess with the original prankster? Then they've got another thing coming."

xxxxxxxxxx

"Okay, so this might be something more than a prank…"

Lupin would have rolled his eyes at Sirius' if he hadn't been feeling so concerned about the welfare of his two students. His friend was pacing in a small circle, having now made the trip over to Hogwarts to help with the search (and potential retribution). That search had so far been frustratingly fruitless, with their legs weary from navigating the many hallways that Hogwarts boasted. After his wasted trip to the Quidditch pitch, Lupin was ready to fall onto any surface that looked remotely comfortable.

"They weren't in the Gryffindor common room," the professor said. "Nor were they in the dorm room. I'm almost glad about that last point. If I'd walked in on something, I wouldn't have known how to handle the embarrassment of the situation."

Sirius chewed on his thumb. "You don't think that's what they're doing, do you? Trying to keep us away whilst they explore the depths of their friendship?"

"Please…don't ever say that again. I'm in a bad state as it is."

"We can't rule out. I remember how teenage hormones work. They stop them from thinking straight, even those as intelligent as Harry and Hermione. They probably don't want us to know for the obvious reasons, as well as the fact they'll be feeling guilty about doing it after Hermione was with Matthew. It's the typical young love triangle, I'm afraid. There's nothing more powerful."

"I think you're getting ahead of yourself. They may be dear friends, but I don't think anything like that is going to happen anytime soon. They're too loyal to Matthew's memory. It's only been a few months."

"It feels like it was yesterday, whilst also simultaneously feeling like it was years ago," Sirius remarked wistfully.

"Can you stop getting side-tracked?"

"This is what I do when I'm panicked! My mind goes on all sorts of tangents. I can't help it."

"Let's focus on what we know so far."

"They tricked you into leaving. And I'm trying very hard not to judge you for being outsmarted by a student."

"Hermione isn't a typical student, if that makes it any better."

"Does it?"

"I'll admit my pride has been wounded quite a bit."

"They're not in Gryffindor Tower. And they're not in their usual haunt, the library. For some reason, Madam Pince wasn't happy to see me again."

"I wonder why," Lupin replied drily. "Perhaps it's because you once accidentally set a pile of books on fire when we were supposed to be revising."

"We were revising the fire charm. That counts as learning."

"Harry and Hermione weren't with Hagrid either. I treaded carefully around the subject matter. I didn't want Hagrid to become an emotional wreck if he thought something had happened to the two of them."

"How did that work out?"

"I got out of there before he started blowing his nose through the tears."

"Where else would they be?"

"Perhaps with Dumbledore? They spend an awful lot of time with him. He might be training them."

"If the old goat is working behind my back, then he's got another thing coming to him."

"But I'm also growing more concerned about one particular fact…"

Sirius hesitated. "I don't know whether I want you to divulge."

"They apparently wanted me to leave my office."

"Which suggests they wanted something that's in here. Is anything missing?"

"I haven't exactly had the time to look around and take stock."

Sirius muttered something under his breath but he wisely kept his voice down so as not to anger Lupin. He set about roaming the office, overturning the odd item that piqued his interest. The professor followed in his wake, trying to remember how things had been before he'd left. Nothing remotely stuck out. And the more he thought about it, the more he wondered whether he had anything of worth or interest in his possession. Especially nothing that would interest two teenagers.

Until he happened to glance at his fireplace, noticing a speck of dirt on the carpet. It was barely noticeable, so much so that Lupin was impressed that he'd spotted it in the first place. It wasn't dirt, strictly speaking, but a small clump of powder that had found its way onto the floor. He could have blamed himself, having used the fireplace to call Sirius. He could have blamed that very man, as if his arrival had knocked over the soot. And yet Lupin couldn't ignore the cold dread consuming him as he inspected the offending mess.

"Sirius…"

His long suffering friend looked at the same spot once he ambled over. "You don't think…"

"...surely they wouldn't be so idiotic and foolish…"

"Do you know who we're dealing with? That's basically their MO."

"They must have learnt it from you."

"You know just as well as I that they were doing things like this long before I returned to the scene. You can't blame me for this mess."

"We don't know whether this is a mess just yet. We could be jumping to conclusions based on their track record, which might be exactly what they want."

"The evidence is pointing in one direction. Unless you know of a way of precisely locating them, our only other option is to scour Hogwarts until they either show up again or we die of old age."

Lupin's eyes lit up. "You brilliant genius!"

Sirius, evidently, didn't have a clue as to why he was receiving praise, but he was always going to accept. "I've been saying it for ages. It's about time that you realised it."

xxxxxxxxxx

"And that's how we know they're definitely not in the school."

Lupin had never felt as awkward as he did in that precise moment. They'd travelled away from Hogwarts, which already highlighted that they were facing a difficult situation. That was confounded by the fact that he and Sirius were standing in front of Katherine and Peter Granger, whose expressions were growing more serious with every second ticked by. They'd even forgotten to ask if the unexpected visitors wanted a hot drink and a biscuit.

Adding to their obvious concern about their daughter, being presented with the Marauders Map was always going to confuse the Muggles. They looked to be torn between being fascinated by the magic on display and being worried about what it represented. Following his bright idea, the professor had searched through Harry's dormitory to find the map, an invasion of the boy's privacy that Lupin would never have considered if the circumstances hadn't been so perilous.

He might have been happy that he'd gone through with it, if it hadn't confirmed his worst fears. Neither Harry nor Hermione were on the Hogwarts grounds. The map had never failed him up to that point, and he wasn't about to start questioning, no matter how much he wanted to dispute its claims. He and Sirius had prayed to find the teenagers' little footprints darting around an obscure part of the castle, if they'd been suspiciously close to one another in a broom cupboard.

No such luck.

"You're telling me that this piece of paper can track everyone in the school?"

Peter Granger was an intimidating figure, regardless of the fact that he didn't have magic at his fingertips. Lupin supposed that was always the job of a father, as if childbirth imbued them with a new sense of authority. His bushy, severe eyebrows and clipped tone were enough to make the professor gulp, looking to Sirius for assistance. Yet the renowned troublemaker, who'd dealt with years of dementors at Azkaban, looked to be just as nervous as he was.

"That's right," Lupin replied.

"And Hermione's not on there?"

"As well as Harry, yes."

"We used this handy item at the end of the Triwizard Tournament," Sirius explained. "So that we could figure out whether they'd been taken. I didn't expect us to be needing its services again so soon."

"Does that mean they've been taken?" Katherine asked fretfully. "Captured by those…Death Eaters? Or their leader?"

Lupin could deal with a lot of things. A class of hormonal children was a piece of cake. A Boggart was a walk in the park. Even contending with his alter ego as a werewolf at a certain point every month was easy compared to facing a tearful mother. He didn't know whether to hug her out of shared concern, fearful that she would lash out and see him as the easiest and closest target. He got enough scars during the full moon without needing to add any others to the mix.

"We have reason to believe that they've gone somewhere through their own volition," he said. "It's highly likely that they've used the Floo network to travel to…well, we don't know where yet. That's why we came here. Your home seemed like the logical destination."

"We were hoping that they were just looking to catch up with the two of you," Sirius added. "I wanted nothing more than to walk in and spot them at the dinner table, or maybe lounging on the sofa to have a break away from the madness of Hogwarts. I might have even been lenient in my punishment if that had been the case."

"With exams coming to end, they might have even been looking to celebrate that achievement."

"Although I would have been quite insulted to find out they didn't want to include me in that party."

"They've probably seen what you're like on the dance floor and wanted to save themselves the embarrassment."

"As if you can talk."

"I'd appreciate it if you could focus on what's really important," Peter interrupted them.

Lupin wasn't about to tell him that, to Sirius, nothing was more important than how cool he viewed himself.

"I can safely say that they haven't come here," Katherine told them. "We would have noticed them walking through the fireplace. But where else would they have gone? Why would they leave without telling anyone?"

"Maybe because they've learnt a bad trait from someone they look up to," Sirius practically growled.

"Who?"

xxxxxxxxxx

"Well, I must say that this is a pleasant surprise."

Dumbledore, as ever, was annoyingly serene as he sat by his desk, watching the assorted party. That was despite the fact that they were all pretty much glaring in his direction. The likes of Katherine had never been afraid to stand up to the headmaster, refusing to be intimidated by a reputation that had no influence in the Muggle world. Now that her daughter was once again in potential danger, she was falling back onto tried and tested habits.

Lupin would have thought that McGonagall's presence would have been enough to make Dumbledore immediately realise the severity of the situation. Instead, it looked to have further piqued his interest, as if he was trying to figure out what sort of events would have brought such a group together. Surely it must have been fairly obvious, with two particular people uniting them. Perhaps, once it was spelled out for him, that glowing expression would promptly disappear.

Apparently, along with the two kids.

"Harry and Hermione have gone," Sirius said briskly.

Lupin was, of course, correct in his assumptions. As soon as the words left the other man's mouth, Dumbledore's face fell. There was no longer a glimmer in his eye. He sat straighter in his chair for a few moments before the restless energy consuming him won out, forcing him to stand up. A weary hand was dragged through his magnificent beard. Even a man as great and as powerful as him couldn't find the bravery to look Katherine and Peter in the eye.

"You're sure of this?"

"Goddammit, Dumbledore! Do you think we'd really be here if we weren't certain?"

"They're nowhere in the school," Lupin explained, a great deal calmer than his friend.

"And they're not at home," Katherine added.

"Grimmauld Place?" Dumbledore asked.

Sirius shook his head. "There are so many charms around that building that I would have known if anyone had walked through the front door."

"I have a grave feeling that I know where they are, if the other alternatives are accounted for."

"You know, I was almost worried that you were going to say that. Worried for your safety, that is. Because if you've encouraged them to do anything reckless…"

"There's no need to be throwing threats around," McGonagall briskly said. "That's not going to bring back Potter and Granger any sooner."

Sirius folded his arms, a touch petulantly. "I'm not making any promises until he explains himself."

"You've been told of our search for horcruxes," Dumbledore began tiredly.

"I didn't like it at the time. I thought it was another way of Harry's childhood being robbed, but we all know how stubborn he can be once he gets an idea into his head. And, thanks to that damned prophecy, I have to accept that Harry's linked to Voldemort until the mad basta-"

"Sirius," McGonagall blurted out.

"...until the Dark Lord conks it. So I can see it as a good thing that you're finding ways to bring that about as soon as possible."

"Hermione wouldn't go into a lot of detail about them," Katherine told the group. "It was either because she didn't think we'd understand the intricacies or she didn't want us to know the finer details."

Peter nodded his head. "It might have been a bit of both."

"But she said that they were linked to Voldemort, and that, by destroying them, that'd kill him in the process."

"That's a neat and succinct summarisation," Dumbledore replied. "I'd expect nothing less from your daughter."

Lupin could easily tell what he was doing. The professor, after his momentary lapse, was falling back onto his default setting. He was attempting to sweet talk his way out of the tricky situation, praising the Granger girl to win back favour with her mother. It was quickly apparent to see that that particular tactic wasn't going to work this time around and, to his credit, the headmaster promptly picked up on the same clues, ceasing his attempts barely after they'd started.

"Why wasn't I told about this, Albus?" McGonagall wondered, a heavy dose of ire in her tone. "They're two of my Lions. I should be made aware of anything that impacts them."

"I've tried my best to keep our knowledge of horcruxes to as small a number as possible, to reduce the chances of it getting out. It has allowed us to act in secret already, which has led to two of these horcruxes being destroyed. Another has been recently procured, though its removal has proved to be more…delicate."

Katherine immediately picked up on his awkward demeanour. "What do you mean by that?"

"The method in which the previous two were dealt with may not be enough to complete the same job this time around, at least not safely. In fact, I put myself forward to handle the problem but the two students refused to put my life at risk. I am grateful and touched to have seen their protection over me, even if it makes me feel even older than I actually am."

"Why do I feel as if you're leading up to something that I'm not going to like?" Sirius wondered.

"I'm getting that impression too," Katherine agreed.

"It was decided that, to reduce temptation, the horcrux would be locked away in the most secure location we had at hand," Dumbledore explained. "Namely, Matthew Mormont's Tardis. Only one person has the key to open it."

"My Hermione…"

"Precisely. Which means that you'll understand my immediate concern that the pair have travelled to Diagon Alley in a foolish attempt to destroy it themselves."

"Hermione wouldn't do something so reckless!"

Lupin wondered whether now was the best time to tell the Granger matriarch that her daughter had been involved in more than enough dangerous events to limit the accuracy of such a claim. But he wasn't a big enough fool to risk having her frustrations focused on him. He much preferred it if it stayed pinpointed on the headmaster.

"I wish I could say the same about Harry," Sirius murmured. "But his worst trait is that he'd rather put his life on the line than someone else. It's also his most commendable characteristic, not that I'm currently thinking of applauding him for running away."

Lupin ran a hand through his greying hair. "Was it really wise to use the Tardis as a hiding place, headmaster?"

Sirius nodded his head, pointing an accusatory finger. "Yes, that's what I'd like to know as well. You locked a dangerous artefact in a place that only a child could access. Surely you must have realised how reckless that is! You were basically telling them to go off on their own!"

"If I may defend myself, I was given every indication that neither of the pair were considering tackling this task on their own," Dumbledore fired back. "Indeed, so much time has passed since we collected the horcrux that I was certain that they were following our agreed plan. We wanted to find another way to destroy the object."

"Do you think that means they've discovered that? Another way that avoids them getting hurt?"

"We can only hope. But there is one positive that we can work with."

Katherine scoffed. "I don't think that's likely."

"Unless Miss Granger has suddenly developed the ability to fly a piece of advanced machinery, the Tardis is currently grounded. We know where its location is, which means we can make our way to Diagon Alley immediately. Let's just hope that we arrive there before they do anything they'll regret."