Written for the Marauder Era Challenge Prompts, ahoy! Using the prompts:

"Can you do me a favor? Grow up or sod off"

scared of heights

Astronomy Tower

dizzy

insomnia

"Is it just me?"

"Please tell me you're joking"

"I can't breathe"

"Can't you see that everything is different now?"

a new addition

Disclaimer: JK Rowling owns the Harry Potter universe and all its characters

Remus woke rather abruptly. He'd always been a light sleeper, woken by the slightest noises. And unfortunately, Sirius was a bit of an insomniac.

Remus sighed in annoyance as Sirius shuffled around in his bed. He squeezed his eyes shut, desperately trying to hold onto any semblance of sleep he'd had just moments before. Sirius lay quietly for a few minutes, and Remus allowed himself to hope they could both actually get back to sleep. But Sirius couldn't make anything easy. After tossing and turning, Remus could hear him ripping back the covers and hangings rather violently. Remus tried to pretend he was still asleep—whenever Sirius realized he'd woken Remus he would apologize profusely and shoot him worrying looks throughout the following day, much to Remus' annoyance. Sirius seemed to stand in the middle of the room, doing Merlin knows what, before padding toward the door and leaving.

As soon as the door clicked closed, Remus sat up. Yes, Sirius was prone to waking up in the middle of the night, but he'd never left the dorm before. He usually sat in his bed, reading by the light of his wand, or he sat on the windowsill, staring out over the grounds dramatically. Remus wondered what had prompted the change. Maybe he wanted to get warm by the fire of the Common Room. Remus contemplated going after him. On the one hand, Sirius' change in schedule wasn't that alarming. And Remus' bed was quite comfortable. But Remus' curiosity was peaked. He loved a good mystery, even a short lived one.

In the end, Remus' curiosity won out. Quietly, as to not wake the others, Remus tip-toed out of bed and down the stairs. When he got to the Common Room, however, Sirius was nowhere to be found. All of the armchairs and sofas were empty. Remus furrowed his brow. So, Sirius had left the tower? Where did he go? The kitchens? Remus turned and climbed the stairs to the boys' dormitories again. He wasn't about to go wandering the castle aimlessly. Upon reaching the seventh year dorm, Remus crept in, shuffling to James' bedside table as quietly as he could. He hadn't been terribly hopeful, but Remus was pleasantly surprised to see the Map there. So Sirius hadn't taken it with him; not one of his smarter ideas, but Remus was grateful. Pulling on his trainers and grabbing his wand, Remus set off down the stairs once more. "Lumos. I solemnly swear that I am up to no good," he whispered. The castle appeared on the parchment, and with the lack of movement from students and professors, the Map almost seemed like a regular map. It made Sirius laughably easy to find. He was moving fast, and it looked like he was headed toward—

That bugger. He was going to the Astronomy Tower.

Apparently Sirius had known Remus was awake. He also knew that Remus was not particularly fond of heights and therefore would most likely not follow him to the tallest tower in school. Remus was sorely tempted to prove him right. Sirius was old enough to take care of himself. If he wanted to sulk in the dead of night, staring off the edge of the Astronomy Tower—a true flare for the dramatic, Sirius had, one not even James could match—then who was Remus to stop him? But what would put Sirius in such a mood that he wouldn't want Remus to follow him? Sirius loved attention, especially when he was upset. He wanted someone to talk to him, but he was too proud to start the conversation, so he would sigh often and audibly, shooting glances at his friends to see if they'd noticed. James, Remus, and Peter had once held a contest to see who would crack first and indulge him. Not surprisingly, James owed the other two a gallon in only a few hours.

By locking himself in the Astronomy Tower, Sirius was clearly communicating that he wanted Remus to leave him alone. But why? Remus groaned as his feet pulled him farther away from the dormitory, from his warm, inviting bed. This mystery was getting more interesting.

About three quarters of the way up the winding staircase, Remus wondered what the hell he was doing. He was shaking, though he pretended it was from the cold night air. As he passed yet another window, he kept his eyes fixed forward, intent on not looking out. But his body betrayed him, and out of the corner of his eyes he saw only the tops of the trees and the clear night sky. Cursing, Remus shit his eyes tightly, willing his heart to slow down. His world swam behind his eyelids and for a frightening moment he thought he was going to be sick. He could only hope to keep it in until he saw Sirius so he could throw up in the idiot's perfect hair.

"Remus?" Speak of the devil. Remus didn't open his eyes—he was confident that he would have indeed vomited on Sirius' shoes if he had—but his grating voice was unmistakable. "I didn't think you'd follow me up here." Remus ignored him, instead focusing on breathing slowly in and out his nose. "Dizzy?" Sirius asked. Remus managed to snort derisively. A beat passed and he heard Sirius' knees pop as he crouched down next to him. Remus hadn't even realized that he was sitting until then. Sirius placed his hands on Remus' shoulders and steered him so he was sitting sideways on the stairs, his back to the wall. Remus leaned against it heavily. The cool stone felt good against the back of his neck and through his shirt. As he began to calm down, he could hear Sirius chanting, "Just breathe, mate. That's right, in and out—"

"Oh, shut up," Remus snapped. "I'm fine now." Sirius averted his gaze from Remus, and the lycanthrope felt a surge of guilt wash through him. Sirius had been trying to help; there was no need to snap at him, even if he was the reason Remus was there in the first place. "Sorry, Padfoot. It's just…You know how it gets—"

"Yeah," Sirius agreed, waving it off. "Don't worry about it, Moons."

Remus nodded, thankful that his friend wasn't pushing the subject. They sat silently for a minute, Sirius inspecting the dirt on the steps as Remus studied him. Remus tried thinking of a delicate way to start the conversation, but decided that he was far too tired and that Sirius was much better at word games than he was, and that a direct approach was probably best. "What's wrong, Sirius?"

Sirius looked up, startled, before dropping his gaze again. "It's not important."

"Sirius, I just about had a panic attack because I came looking for you to find out what's bothering you," Remus all but snarled, "so you'd better bloody well tell me." Sirius gulped. Remus didn't curse often, and it had clearly caught the animagus' attention. "Now."

"It's just that," Sirius started, but he stopped himself. He sighed, and then it all came out in a rush. "I'm happy that James is happy—I mean, I never thought he'd actually get the girl, but I'm glad he finally did—but now that he and Lily are together he doesn't have any time for us, and I just miss having him around and I resent Lily for taking him away, but I don't want them to break up because she makes him happy, but I also kind of do because it's making me really unhappy."

Remus' eyebrows disappeared into his hairline. Sirius was breathing hard and eying Remus timidly. "That's, erm…that's a lot to take in at—wait, what time is it?"

"Four-ish, I think."

"At four o'clock in the morning," Remus finished.

When he offered nothing more on the subject, Sirius prompted, "Well?"

"Well, what?"

"Is it just me?"

"Yes."

Sirius exploded. "But, Moony!" he yelled, throwing his hands up in the air. "She's stealing him away! She's making it so he never hangs out with us and she's turning him into someone else! Oh, Merlin," his voice dropped down to a hiss. Remus had trouble following his friend. The wild, disbelieving look in Sirius' eyes was worrying. "That's what this is all about, isn't it?" Sirius continued, his whispers echoing in the stairwell. "She doesn't really fancy him, this is just a plot to break us all up—"

Remus grasped both of Sirius' shoulders, hard, and shook him. "Stop," he commanded. "Just stop. Please tell me you're joking."

Sirius' lip twitched. "I'm serious."

Remus growled and shoved Sirius away from him. Straightening and dusting himself off, he began down the stairs determinedly, albeit a little shakily. "Can you do me a favor?" he asked over his shoulder, suddenly incredibly weary. "Grow up or sod off."

He made it down about ten steps before Sirius called out. Sighing, Remus stopped but refused to turn around. Not for the first time, he regretted coming after his friend. "Remus, I—I'm sorry, alright? I've just been so worked up and I can't sleep and usually James practices Quidditch with me when I'm like this so I'm tired and I can fall asleep, but since he hasn't been around I just—" Sirius took a deep breath and muttered something to himself that sounded suspiciously like "Sometimes I just feel like I can't breathe."

Remus turned now to see Sirius still sitting on the step he had left him on, head bowed so his hair covered his face. Bloody dramatic idiot. "Have you talked to James about it?" Remus asked.

"Yeah," Sirius sighed. "He just told me to try to get along with her."

Remus failed to see the issue. "And that's a bad idea because…?"

Sirius ran a hand through his hair exasperatedly. "Because I'm afraid that I'll start to like her and then I can't hater her and blame her for anything." Remus laughed. It was typical Sirius, wanting to blame anyone but himself for the feelings he couldn't verbalize. Sirius looked up sharply. "Oi!" he protested. "It's not funny! Can't you see that everything is different now?"

Remus smiled tiredly. He wanted to climb the stairs to sit next to Sirius, but his feet wouldn't let him. "Yeah, I know," he called up to his friend. "But it doesn't have to be a bad thing. You're making it out to be a lot worse than it actually is." Sirius opened his mouth to protest, but Remus talked over him. "Don't think of it like we're losing James. Think of it like Lily is a new addition to the Marauders."

"But it'll just be the two of them off on their own a lot and—"

"How do you think Peter and I feel?" Remus interrupted exasperatedly.

Sirius hesitated, furrowing his eyebrows. "What do you mean?"

Remus sighed. "Have you ever thought that it's been that way for Peter and me all along? Except that instead of James and Lily, it was James and you always leaving us behind." This effectively shut Sirius up. "Look, Padfoot, I know he's your best friend and that you're feeling a bit of separation anxiety. But you aren't literally attached at the hip. James is his own person and he has a right to do what makes him happy. And if you really are his best friend you won't make this harder than it has to be."

Sirius stared off into space for a while, lost in his own thoughts. Remus waited patiently, eyelids drooping. He had just about convinced himself that he could fall asleep standing up when Sirius asked, "What do I do?" Remus smiled in triumph.

"You'll be civil toward Lily—she's friendly, I swear. Give James his space—if you ask him to do something but he says he already has something planned with Lily, don't get angry or feel rejected. Just try to reschedule. I promise, James doesn't love you any less just because Lily is around." Sirius nodded, looking at Remus earnestly. Remus suddenly felt like he was talking to a child about his father dating after a divorce. "And if you're ever bored or lonely or out of sorts, and James is away with Lily, please come and bother me. I might be annoyed, but I won't turn you away. I just want to help." Sirius smiled and nodded again in thanks. "Good, now that that's all sorted, can we please go back to bed?"

Sirius chuckled to himself and trotted down the stairs to meet Remus. He casually tossed an arm around the lycanthrope's shoulders, and Remus knew it was a wordless gesture of support as they descended the steep steps. Remus nudged Sirius in the ribs in wordless thanks.

When they reached the bottom, Sirius did not remove his arm from Remus' shoulders. "I just…erm, thank you," Sirius stuttered, training his eyes on the ground. "You know. For following me. I know how much you hate heights."

"No doubt why you chose the Astronomy Tower," Remus grumbled. Sirius chuckled and rubbed the back of his neck guiltily.

They walked in silence until they reached the portrait hole. After reciting the password to a very cross Fat Lady, Sirius piped up again. "And, you know, I never meant to, well, leave you out—"

Remus rolled his eyes. "Oh, can we cut the sentimentality already?" He roughly shoved Sirius through the portrait hole, eliciting a dangerous rumble of laughter from the Pureblood. "I've filled up my quota for the whole year, at least!"

Sirius' grin glowed in the darkness. I'll get you for that, Lupin, just you wait," he threatened as they ascended the stairs.

"Until tomorrow?" Remus asked hopefully as they stepped through the door to their dorm.

Sirius yawned and flopped heavily onto his bed without bothering to take off his shoes. "Until tomorrow," he agreed sleepily.

Remus rolled his eyes and toed off his shoes. He placed the Map and his wand on his table and crawled under the covers, praying sleep take him quickly lest he wake up cocooned in Sirius' dirty socks.