Disclaimer: I defer to Rowling and the entity known as Moftis.

Harry asked Remus about anti-dementor lessons the moment class ended on the first day back from holiday break. Even though Remus could already tell he was going to have a busy term, he was also excited to work with James's son on advanced magic, so he suggested meeting at the first time he'd be free: Thursday night at eight o'clock.

Holding the lesson meant finding a way to force Harry to stand up to a dementor, hopefully without having any contact with an actual dementor and certainly without bringing one into the school. The conundrum bothered Remus enough to keep him up on Monday night, and around one in the morning his brain finally stopped feeling like it was trying to force together to pieces from different puzzles, and actually gave him something he could work with.

Harry had said what he feared most was a dementor.

Therefore, Remus needed to find a boggart. He could almost see Sherlock thrusting his hands heavenward and exclaiming, "Obviously!" It was a nice thought. There was something unreasonably comforting about picturing Sherlock acting condescending. With that image in his mind, Remus fell asleep.

Boggarts weren't just everywhere, although a place as big and old as Hogwarts probably had to have a couple hanging around during any given week. Still, again given the size of Hogwarts, there was no guarantee of running into boggarts with anywhere near that frequency. As a result, Remus spent most of his breaks on Tuesday, Wednesday, and Thursday searching the castle for boggarts. This meant opening drawers, cupboards, and doors into closets, all of which amounted to rather suspicious behavior. Remus wished he had James's invisibility cloak, but in the end he managed to mostly time his searches of rooms so that no one would run into him. On the few occasions he did get caught, well, he'd spent the last two years doing damage control when Sherlock was caught snooping where he shouldn't have been, and much of his time at Hogwarts trying to spin excuses for the Marauders. It wasn't like this was his first time in a tight corner.

On Thursday, Remus was starting to get desperate, so he snuck down to the dungeons and began poking around Filch's quarters. This was the last place in the castle he'd like to be, but he was determined not to let Harry down, and he'd already searched for boggarts in almost every other nook of the castle.

Remus let himself into Filch's office and tried not to shudder as he remembered all of the times he and his friends had been dragged in here by their ears. He could still recall Filch muttering, "Filth and slime and muck and gore! You think it's funny, do you? Really funny. Just hilarious, me cleaning up after you lot day after day. Don't know why Dumbledore insists on keeping children around here. We could run the school just fine without 'em . . ."

Remus threw off the memory as best he could and began searching the office. There was a whole army of filing cabinets along the back wall, and Remus noted with some pride that the Marauders still had an entire drawer to themselves. So, he realized, did the Weasley twins. Remus smiled at that. He knew that, as a professor, he was supposed to care about rules and orderliness, but the corridors of Hogwarts were just so much more fun with the twins about, so much more alive.

Remus opened the drawer labeled "Moraders"—come on, Filch, learn to spell—and suddenly found himself face-to-face with Sirius Black.

Of course the boggart would be here; of course Remus would find it now. Of course Si—Black—would spurt out of a drawer marked with the name of the group that had once included both himself and Remus, just when Remus was feeling nostalgic about being an annoying rule-breaker. Of course he would show up just when Remus was least prepared to deal with him.

Remus drew his wand, having been stupid enough to stop having it at the ready after so many fruitless searches, and said, "Riddikulus!"

Sherlock appeared, just as he had the last time Remus had encountered a boggart. "Obviously you're one of those wizard folks, like John," Sherlock said, and this gave Remus the leverage he needed to push boggart-Black back into the filing cabinet and slam the drawer shut (which shouldn't have been possible, but magic seemed to trump geometry and physics within the walls of Hogwarts at times like this). Remus caught the befuddled look on Sherlock's face just before he disappeared as the Riddikulus Charm wore off.

With the boggart now making a racket in the cabinet drawer, Remus cast about for a box of some sort. There was a packing case in one corner; Remus summoned it and then muttered some spells he'd learned in his first year living on his own after Hogwarts, and the entire drawer from the filing cabinet transferred itself into the box, which then shut tightly. Remus levitated the box in front of him and was just walking out of Filch's office when the caretaker himself stumped in.

"What are you doing here?" Filch growled. "Stealing my records on all of your crimes so I can't get Dumbledore to punish you?"

"I don't think Dumbledore would punish me anyway," Remus said mildly, finding it relatively easy to force a smile. He wasn't as stubborn as Sherlock when it came to suffering fools. "I'm a professor now."

Filch bowed, his greasy hair falling forward in lank lumps as his top half tipped downward. Remus took his opportunity to exit, not even staying to watch Filch straighten up or listen to him say, "Very sorry, professor. Quite right."

Having finally found the boggart, Remus spent the rest of the day teaching, and then he tried to get a start on grading in between dinner and when he was supposed to meet Harry. He should have set an alarm to get him out of his office, because he was so intent on finishing just one more paper that he didn't leave until his clock said two minutes to eight, and, by the time he made it to the room where he'd promised to meet Harry, it was five minutes after their specified meeting time.

All of the lamps were lit in the History of Magic classroom when Remus arrived, which could only have been Harry's doing, and Remus was vaguely proud of him for having both the good sense and the ability to do such a spell without waiting to be told. Now, the boy was seated in a desk in the fourth row back—a bit further forward than the Marauders had normally sat, but not much. Remus could only suppose it was Harry's usual seat for History of Magic. When Remus entered the room, Harry hopped out of the desk and came forward to meet him.

"What's that?" Harry asked as Remus set the packing case on Professor Binn's desk.

Remus removed his cloak and threw it over the chair at Professor Binn's desk. He didn't suppose it was really Professor Binn's chair, given that ghosts couldn't sit and therefore didn't need any chairs, but it went with the desk. "Another boggart," Remus explained. "I've been combing the castle ever since Tuesday, and very luckily, I found this one lurking inside Mr. Filch's file cabinet. It's the nearest we'll get to a real dementor. The boggart will turn into a dementor when he sees you"—Remus was fairly certain about this, insofar as he could be about anyone's predictions as to the shape their boggart would take, given Harry's readily apparent self-awareness—"so we'll be able to practice on him. I can store him in my office when we're not using him; there's a cupboard under my desk he'll like."

"Okay," said Harry, his voice full of badly done bravado. Still doesn't want to seem weak.

Remus took out his wand and motioned for Harry to get his out as well. There was no sense dithering about technique without at least gripping the instrument of implementation. "So . . . The spell I am going to try and teach you is highly advanced magic, Harry—well beyond Ordinary Wizarding Level. It is called the Patronus Charm."

"How does it work?" Not even bravado; just nerves.

"Well, when it works correctly, it conjures up a Patronus, which is a kind of anti-dementor—a guardian that acts as a shield between you and the dementor. The Patronus is a kind of positive force, a projection of the very things that the dementor feeds upon—hope, happiness, the desire to survive—but it cannot feel despair, as real humans can, so the dementors can't hurt it. But I must warn you, Harry, that the charm might be too advanced for you." It took your father three years to become an Animagus, and in its own way this is nearly as hard. "Many qualified wizards have difficulty with it."

"What does a Patronus look like?" Some of the nerves were gone, lost to an apparent wave of curiosity. Good.

"Each one is unique to the wizard who conjures it." Remus decided not to mention that a wizard's Patronus could change forms after the wizard went through intense emotional changes, like falling in love or losing a loved one. Harry could figure that out on his own, and it wasn't particularly relevant at the moment.

"And how do you conjure it?"

"With an incantation, which will work only if you are concentrating, with all your might, on a single, very happy memory."

Harry's eyes settled into a position Sherlock had often pointed out to Remus, directed toward the top left corner of the field of vision. It was the position people's eyes tended to assume when they attempted to recall true information. Remus felt good about that at first, since obviously Harry was taking the assignment seriously; then, as the minutes ticked by, Remus's stomach began to sink. What was taking so long? Harry's face didn't shift at all; it definitely didn't go into what Sherlock had called "decision mode," when people's eyes would bounce from one fixed point to another as if actually looking from one option to the next.

After five minutes, Harry was still trying to summon up a memory. What was so hard about this? Any childhood breakthrough would do, at least for a first attempt. His first time riding a bike, a really great ice cream cone . . .

At the seven minute mark, Harry's eyebrows had started creeping together over eyes that were still fixed on a point up and to the left, and Remus realized that Harry's childhood must have been miserable.

Remus had received an owl from James a few days before Christmas, 1979. The note had simply said, "Great news. Come quickly." Remus had Apparated to the Potters' right that moment, barely bothering to wonder what this all was about.

Peter and Sirius were already there in the living room. That made sense; they lived closer to Godric's Hollow than Remus did, so the owls hadn't had to cover as much distance. When Remus appeared, James hopped up from the couch and engulfed him in a hug so big that it made it hard to remember that Prongs was actually the second-shortest Marauder.

As soon as the hug was over, James pulled back and grinned at his three friends. "Lily's pregnant!" he exclaimed, practically glowing with excitement.

The other three had started babbling praise almost as soon as James finished his last syllable. Sirius and Peter bobbed up and down, Sirius actually jumping—leaping, practically—and Peter just bouncing in that way he had.

Once the excitement had finally calmed down, James said, "I've asked Pads to be godfather, and he's accepted—but, Moony and Wormtail, I still want you in my kid's life. I want you all to be like his uncles. Or her uncles. Because, I mean, we already know we make a pretty great family, right? Marauders forever! And think how lucky this kid is going to be, just being born into this family. That's gotta be how it goes."

Remus had failed.

One of James's last requests, and he'd failed.

At the eight minute mark, Remus was drawn from his self-hatred when Harry said, "Right."

"The incantation is this," Remus said, and those four words were more than enough for Remus to realize just how thick his voice was. He cleared his throat and tried to do the same to his mind. "Expecto patronum!"

"Expecto patronum, expecto patronum."

"Concentrating hard on your happy memory?" It had to be something at Hogwarts.

"Oh—yeah—Expecto patrono—no, patronum—sorry—expecto patronum, expecto patronum." A wisp of silver gas coalesced at the end of Harry's wand faster than Remus had expected it to. Harry noticed it, too. "Did you see that? Something happened!"

Remus smiled. "Very good. Right, then—ready to try it on a dementor?" This was mostly because the first memory was rarely good enough. Remus couldn't think of a better way to tell Harry to switch memories than by shattering this one with the boggart-dementor. He felt bad about it, though; it had been so hard for Harry to pick his first memory that he couldn't imagine there was a stockpile of happiness anywhere in the boy's being.

"Yes," said Harry with unexpected firmness.

Remus opened the packing case, and the boggart-dementor rose from it. As the lamps around the room went out and a chill filled the space left by the absence of light, Remus decided he had to hand it to Harry. The kid really did know his own deepest fear.

And then the dementor began to take effect. Remus hadn't been sure it would affect him, since it was Harry's boggart, but clearly it did, because, in his head, Remus heard Sherlock: "Okay, look up. I'm on the rooftop. I—I—I can't come down, so we'll just have to do it like this."

Then the voice stopped as the dementor turned into Sirius Black, which Remus did not find at all comforting, especially given that Harry Potter was now lying helpless mere feet from the man who wanted to murder him. "Riddikulus!" Remus managed, and the sight of Sherlock (looking alive, at least in this form) made Remus feel so much better that he found the strength to shove boggart-Black back into the packing case and slam the lid shut.

Then Remus turned back to the now-gloomy, now-dark room and lit the lamps with one wave of his wand. (That was a fun spell, though the time Remus had devoted to practicing it back in his sixth year could probably have been better allocated.) That done, he walked over to Harry and knelt beside the prone boy, who was lying face-down on the floor, still unconscious. Remus knew—though he couldn't remember where he'd first learned it—that returning to consciousness and finding oneself face-down was an experience that did not recommend itself for repetition, so he rolled Harry over onto his back before trying to wake him.

"Harry!" Remus said once the boy was properly situated.

Harry's head jerked at least three inches off the floor, and Remus slipped his hand into the space between the floor and Harry's head lest the boy knock himself out again. When Harry's head hit Remus's hand, he muttered, "Sorry," and sat up.

"Are you all right?"

"Yes . . ." Harry needed the help of a desk just to drag himself into standing position.

Remus pulled out a chocolate frog and handed it to Harry. "Here. Eat this before we try again. I didn't expect you to do it your first time; in fact, I would have been astounded if you had."

"It's getting worse." Harry bit off the Frog's head. Was he putting it out of its misery? "I could hear her louder that time—and him—Voldemort."

Lily. "Harry, if you don't want to continue, I will more than understand—"

"I do!" Harry consumed the rest of the Chocolate Frog in one gulp, a feat reminiscent of Si—Black. "I've got to! What if the dementors turn up at our match against Ravenclaw? I can't afford to fall off again. If we lose this game we've lost the Quidditch Cup."

So much like his father—everything in service of a meaningless athletic title. "All right then . . . You might want to select another memory, a happy memory, I mean, to concentrate on . . . That one doesn't seem to have been strong enough . . ."

This time Harry's eyes only stayed fixed in the top left corner of his vision for two minutes. Perhaps his life hadn't been completely horrible, then.

"Ready?" Remus asked when Harry's eyes focused back on him.


Remus opened the box again. "Go!"

The dementor made everything dark and chilly and awful as it advanced on Harry, and Remus suddenly heard a voice inside his head. "The newspapers were right all along. I want you to tell Lestrade, I want you to tell Mrs. Hudson and Molly. In fact, I want you to tell—"

And then the voice cut out and Remus found himself staring once again at Sirius Black.

It was not a good night.

The Riddikulus Charm took three tries to take effect, and boggart-Black managed to say some seriously chilling things about Harry before Remus was able to banish him back into the packing case. Remus tore open a Chocolate Frog and ate the whole thing before he even bothered re-lighting the lamps and waking Harry.

This time, when Harry awoke, he had a long moment of disorientation. It pained Remus to see someone so usually bright and active lying in helpless confusion, but what came next was worse.

"I heard my dad. That's the first time I've ever heard him—he tried to take on Voldemort himself, to give my mum time to run for it . . ."

Harry, the frequently bravado-drunk teenager, was crying. It was only abundant experience in hiding grief that kept Remus from doing the same. When Harry pretended to tie his shoe to hide his face, Remus didn't call his bluff.

"You heard James?" Remus could hear the emotion in his own voice.

"Yeah . . ." Harry looked up, and the tears were gone. "Why—you didn't know my dad, did you?"

"I—I did, as a matter of fact. We were friends at Hogwarts." We were Marauders. We were inexplicable. We were amazing. All of it, past-tense. "Listen, Harry—perhaps we should leave it here for tonight. This charm is ridiculously advanced . . . I shouldn't have suggested putting you through this . . ."

"No!" The bravado was back as Harry forced himself to stand without the aid of a desk this time. "I'll have one more go! I'm not thinking of happy enough things, that's what it is . . . Hang on . . ."

Remus wanted to say that, if there were anything happy enough in Harry's miserable life to allow him to conjure a proper Patronus, he would have found it by now, but Remus knew from himself and from soldiers and from the Baskerville client that sometimes memories surfaced at odd times, both opportune and otherwise. He had some amount of faith in Harry's ability to find such a memory. But was it worth it? Harry was doing this in preparation for a dementor invasion of the Quidditch pitch, an invasion Remus was nearly certain Dumbledore would be able to prevent. In that case, what was the point of all this pain and struggle?

"Ready?" Remus asked when he noticed Harry looking at him. "Concentrating hard? All right—go!"

Remus unleashed the boggart-dementor, which had its usual effect on the room.

"Keep your eyes fixed on me. Please, will you do this for me?" Remus heard.

"EXPECTO PATRONUM!" Harry was shouting, meanwhile.

"This phone call, it's . . . it's my note."


"That's what people do, don't they? Leave a note."


"Goodbye, John."

An enormous blob of silver burst out of Harry's wand, and Remus clenched his fist around his wand and screamed, "Riddikulus!"

Remus stepped between Harry and the transformed boggart, hearing a crash behind him as he did so. Probably Harry collapsing. That was good, all told, because it would hardly do for Harry to run into Remus's boggart. Remus shunted boggart-Black into the packing case as fast as he possibly could and then returned to the fallen Harry and helped him sit up.

"Excellent!" Remus managed once Harry was upright again. "Excellent, Harry! That was definitely a start!"

"Can we have another go? Just one more go?" Bravado, but also an earnest longing to learn the spell properly. Motives were hard to disentangle.

"Not now. You've had enough for one night." And so have I. Remus pulled out a bar of Honeyduke's best chocolate that he'd bought specifically for this occasion. "Here. Eat the lot, or Madam Pomfrey will be after my blood. Same time next week?"

"Okay. Professor Lupin? If you knew my dad, you must've known Sirius Black as well."

Remus spun around fast enough to feel his hair lift off his head with inertia. "What gives you that idea?" You can't turn on me. Not you of all people.

"Nothing—I mean, I just knew they were friends at Hogwarts too . . ."

"Yes, I knew him. Or I thought I did. You'd better be off, Harry, it's getting late." And we are really, really, really not having this conversation.

A/N: Feel free to review, but bear in mind that the next few chapters are already written.