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Post Scriptum by academica

Format: Novel
Chapters: 20
Word Count: 72,807

Rating: Mature
Warnings: Strong Language, Strong Violence, Scenes of a Sexual Nature, Substance Use or Abuse, Sensitive Topic/Issue/Theme, Contains Spoilers

Genres: Drama, Fluff, Angst
Characters: Lupin, Snape, Sirius, Kreacher, Lily, James, Regulus, Pettigrew, OC, OtherCanon
Pairings: James/Lily, Snape/Lily

First Published: 01/05/2012
Last Chapter: 08/16/2013
Last Updated: 08/16/2013

 Alluring banner by moriarty.@TDA || Brilliant title by Anatkh@TGS

Lily thinks Sirius and Regulus should make up.
Regulus thinks Lily should give Severus another chance.
So they strike up a deal based on their mutual interests.
Holding up one's end of the bargain, however, is harder than it seems.

May 2012 Featured Story at TGS | 2012 Dobby Finalist for Best Novel & Most Original Story

Chapter 5: Catalyst

The bright gold piece of metal, with its ruby red face and smooth, rounded edges, turned over in Lily’s hand before her eyes, the cool surface of the object and the prominent single letter stamped into it folding slowly and deliberately against her palm. She had received it in the post over the summer and tried it on in the mirror at least a thousand times, but now, on the day when it would take on real meaning for the first time, she was almost too afraid to pin it to her sweater.


She looked up to see Ellery, pausing in front of her with a plateful of breakfast. She smiled, quirking an eyebrow at her friend. “I think you have enough there for an entire season.”

“I’m just so out of shape! I have to be ready for a grueling first practice,” Ellery replied. “But listen, enough about me… how was last night? You did go, didn’t you?”

“Sure, I went,” Lily said, watching an intrigued expression spread across her friend’s face with amusement. “It was fun, until dinner was interrupted by Peeves.”

“Peeves went all the way down to Slughorn’s office? He’s gotten a bit daring.”

“No, no, he held the meeting in the trophy room,” Lily corrected. “You remember, Slughorn is always complaining that his office is too cramped. I’m sure he couldn’t resist a chance to get out.”

“I’m certain,” Ellery agreed. “Did you see anyone interesting there?”

“Oh, of course. It’s the best and brightest,” Lily said sarcastically, trying not to roll her eyes.

“Not even...?” Ellery began, but her expression faded with Lily’s. “Really? I’m surprised.”

“I’m not. He’s never been terribly social,” Lily said, glancing down at the forlorn-looking English muffin on her plate. She suddenly had the feeling that her appetite was gone for good.

“Well, yes,” Ellery said. She was in the middle of trying to figure out to which subject the conversation should shift when Celestina began to approach, looking as if she were in quite the sour mood. Lily cleared her throat, indicating that Ellery might want to vacate the girl’s space.

“See you both tonight after practice?” Ellery said, moving aside as Celestina plopped down.

“Yes, I think we should start with Charms. It’ll be good practice for Flitwick’s first exam,” Lily said, glancing over at her fellow Gryffindor and setting her Prefect’s badge down on the table.

“Do you lot ever stop studying? Must be terribly boring,” Sirius said, leading his friends to the table and taking a seat next to Celestina without acknowledging her.

“Well, Prefects have to at least try to set an example,” Remus said, taking the place next to Lily. “Right?” he added, smiling gently at her.

“Right,” Lily replied, smiling back. She had almost forgotten that Remus was going to be her partner in rule enforcement for the term. Maybe it wouldn’t be so intimidating after all.

“So I suppose last night will be the only fun we can expect from you this term, Moony?” Sirius said, and in a split second his playful expression turned to a grimace of pain, accompanied by a sharp thump under the table. The victim of the assault shot a cold look at James, to his left.

“Moony?” Lily looked over at Sirius. “Why did you call him that?”

“Moody. That’s what I said. Moody,” Sirius corrected. “He needs his beauty sleep.”

“Right, yes, no more late nights for me,” Remus said, glancing over at Lily.

Lily smirked, but part of her felt a little concerned. Late nights? Sure enough, all four of them had purple bags beneath their eyes. What had they been up to? …And why did she even care?

“Well, Lily had a great night, too,” Celestina said, and Lily looked over at her, surprised to hear her speak behind her rumpled sweater and chilly expression. “Isn’t that right?”

“I just went to Slug Club,” Lily said, confused.

“Yes, the tart stains on my dress will be a lasting reminder of that,” Celestina said venomously.

“Oh…” Lily frowned. “I’m sorry, Celestina, I meant to put that in my laundry bin, not yours. I’ll make sure it gets washed for you.”

“You’d better,” Celestina said, but her expression was already lightening. “Otherwise, I won’t have anything to wear for my date with Sirius this weekend,” she added with a playful grin.

“You have a date?” Lily grinned.

“No, not yet. But it’s only a matter of time, I’m sure,” Celestina said boastfully.

“You’re in the Slug Club?” The group turned their attention back to Sirius, who suddenly seemed quite interested in the girls’ conversation, though he appeared to have missed Celestina’s comment completely. The girl in question frowned, poking pointlessly at her cereal with a spoon.

“Yes,” Lily replied. “In fact, I met your brother there last night. He seems nice.”

“I’ll bet,” Sirius said in a low tone, diverting his attention back to what remained of his breakfast.

Lily frowned. “He said to tell you hello.”

“No, he didn’t,” Sirius replied, stuffing the last bit of toast into his mouth and standing up. “Go on, finish up, you lot. I want to spend my free morning out in the sunshine while it’s still warm.”

“Sounds good,” James said, avoiding eye contact with Lily as he rose to his feet. “Peter?”

“I have Arithmancy,” Peter said, looking every bit as if he regretted signing up to take it.

“Lily and I were assigned the first patrol for today,” Remus said, taking a final sip of pumpkin juice. “But go on, save me a place under a nice, shady tree. We’ll be done in an hour.”

“Will do,” Sirius said, slinging his half-empty schoolbag over his shoulder. Then, without another word, he and James disappeared into the crowd of students leaving the Great Hall.


“I don’t know why we have to learn this. Mum just buys it from the Apothecary,” Wilkes said, wrinkling his nose as he carefully opened the small vial of Horklump juice, watching the pale yellow liquid swish around in the tube, leaving a slimy-looking residue on the glass walls.

“Because, you git, if you don’t take your classes more seriously, you won’t graduate, and then you won’t have money to buy anything from the Apothecary, or anywhere else, really,” Regulus said smartly, smirking at his friend as he turned to the appropriate page in Magical Drafts and Potions. “Unless, of course, you’re just planning on living with your mum and dad forever.”

“Not likely,” Wilkes replied, but he couldn’t help but crack a grin.

The two of them were seated in their usual location adjacent to Slughorn’s desk, crammed into the tiny Potions laboratory with twenty-three of their fellow fifth-year Slytherins. Regulus had been looking forward to Potions, despite the fact that it was held in a tiny, freezing classroom, because it was one of the only classes he wouldn’t have to share with students from other houses. Slytherin was not immune from the chance inclusion of a thick-brained student, but its tendency to select primarily from pureblood families at least ensured that most of its students would not be unduly shocked by what they found at Hogwarts. He couldn’t count the number of times in previous years when a Muggle-born student had panicked because she didn’t know how to get a spilled solution stain out of her robes or because she had not been made aware as a small child that a Venomous Tentacula leaf sheds its poison when it dies, rendering it harmless to the touch. In this respect, at least, Regulus had never doubted the comments his parents made about blood.

Wilkes waved a hand to clear some of the smoke from an early mistake out of the air surrounding them, and then he glanced over at the recipe. “Do not drink this potion.” He chuckled slightly. “Sounds like a good way to test the first years’ resolve.”

“I don’t fancy going to Azkaban,” Regulus commented, looking down below the warning and the ingredient list for the instructions on how to brew the Herbicide Potion. “Add four lionfish spines, crushed into a rough powder.”

“You got it,” Wilkes said, working the spines with the pestle until they were reduced to a sandy mixture of orange and white particles. “Do I put it in now?”

“Yeah,” Regulus said, sliding the book closer to him. He could read.

“All right, now we just have it let it brew for a bit,” Wilkes said. Apparently he could.

“So I see that you recovered from the opening feast,” Regulus said, smirking at his friend.

“Slept in late this morning. Wasn’t in the mood for breakfast,” Wilkes replied, making a face at the mere thought of food. “Didn’t eat much yesterday either, really.”

“You going to eat lunch?”

“I should,” Wilkes said, drumming his fingers on the wooden table. “How was Slug Club, then?”

“It was all right,” Regulus said. He almost began telling his friend about the food, but stopped himself just in time. “Peeves and the Bloody Baron sort of crashed the party, though.”

“Oh, yeah?” Wilkes smirked. “Good old Peeves. I’m sure the Baron ripped him a new one.”

“I dunno. Slughorn had me off doing dishes with the elves.”

“Now I’m glad I wasn’t invited,” Wilkes said, standing up to check the potion. “Meet any girls?”

“No,” Regulus said, thinking of Lily.

“I figured as much. Not sure I’d want to date a girl who was really into potion-making.”

“Well, it’s not just that. He invites all kinds of people. You just have to be good at something.”

“Well, what are you good at?” Wilkes replied, smirking over at Regulus.

“Being a Black, of course,” Regulus shot back with a grin, but he turned his attention back to the textbook. “Here, put in the Horklump juice now, before it boils any more than that.”

Wilkes did as he was told, and the two boys watched as the potion turned to the expected shade of lavender. From his desk, Slughorn smiled approvingly at them, nodding to signify pleasure.

“Now, two blobs of Flobberworm Mucus.”

“Just one,” Wilkes said, measuring it out.

“What?” Regulus looked at him, confused.

“Just one,” Wilkes repeated, dropping it in. The potion faded to a concluding simmer.

“Why?” Regulus asked, double-checking the book. No, it definitely said ‘two’.

“Trust me,” Wilkes said, lowering his voice and moving closer to Regulus so as not to be overheard. “Snape told me. He said he was the only one who got it right last year, and purely on accident. Slughorn was thrilled.” He smirked. “Bet he was too busy staring at that Mudblood.”

Regulus considered this for a moment, and behind him a pair of girls groaned as their two-blob potion began to boil more instead of less. “What else has he told you?”

“Nothing,” Wilkes said. “But he’s written it all down. You can hardly read his textbooks.”

Then, there was a disgusting sound, and the cauldron across from theirs broke toward the bottom, a small tidal wave of green mucus spilling out of the hole created by all of the acid. The two Slytherins – half-bloods, Regulus noted – looked up guiltily as Slughorn approached.

“You added in three blobs, didn’t you? Two! Two!” Slughorn looked every bit like a toad about to burst. “Go on, then, clean up. Mr. Wilkes, you have experience with these messes, don’t you?”

Wilkes frowned. “Not this year, Professor.”

“Well, come on, be a good sport and help your housemates,” Slughorn said, his tone returning to its usual civility. “The rest of you, class dismissed… good work…”

Regulus patted his friend on the back as he left. “I’m heading outside. I’ll save you a tree.”

“Yeah,” Wilkes replied, scowling at the mess. “See you in a few hours, if I’m lucky.”


The sunshine warmed Regulus’s face as he stepped out of the castle, heading down to the lake with his bag slung over his shoulder. He had never heard of the giant squid actually dragging away any victims, and so he was planning to take his chances and dangle his feet in the cool water. However, as he approached the edge of the pool, he happened upon a familiar sight.

“Making more corrections?” he asked, sitting down next to the older boy who was occupying the space under the tree closest to the lake. Severus was bent over his Potions textbook, murmuring to himself as he crammed a good deal of writing in his tiny scrawl next to the ingredient list.

“Snape?” Regulus was not entirely sure that he’d been noticed.

“Shh,” Snape said, glancing up at him briefly through his curtain of hair. “They’ll hear you.”

Regulus glanced over to the lake, where he could make out his older brother and Sirius’s obnoxious friend, James Potter, lying sprawled out in the grass. He looked back at Snape, making the mental connection, and set his bag down gently so as not to make much noise.

“Wilkes showed me your little trick with the flobberworm mucus,” he said quietly.


“It worked. The people next to us melted their cauldron.”

Snape smirked at him, a brief show of his pride in having improved upon the recipe, but then his face returned to its usual annoyed expression. “Be sure you make a note of it for the exam.”

“Actually, I was hoping you’d make a few more notes for me,” Regulus said, fishing out his Potions textbook and setting it down in the grass next to Snape’s. “I’m perfectly good at Potions, but being in the club, I think his expectations are just going to keep going up…”

“Make them yourself,” Snape said, clearly insulted by the request. “I don’t know how you expect to get anywhere in life, Black. Any idiot would have noticed that two blobs would be too much.”

“I suppose you’re the only one, actually,” Regulus said coldly.

Snape looked up at him. “You’re no better than your useless brother… disgrace to the house…”

“Don’t say that,” Regulus growled, but Snape’s attention had already been stolen away from him and returned to the two boys sitting on the far side of the field. “You looking for her, then?”

Snape’s eyes shot back to him. “How would you know that?”

“You’re always looking for her, it seems,” Regulus replied. “But you know she won’t be with him. She hates Potter, almost as much as she hates my brother.”

“I’m not sure that’s the case any longer,” Snape said, and he had never sounded so sad.

“If you like her so much, why would you be looking to see her with him?”

“Keep your voice down,” Snape admonished. “I—I’d just like to see her, that’s all.”

Regulus stood up then, unable to participate in the conversation any longer. Being a Slytherin, Snape was likely a pureblood, and his fixation on the Mudblood girl was beginning to turn Regulus’s stomach. “I’m going to go fly for a bit. I’d ask you to join me, but you don’t seem the type.”

“I’m not,” Snape replied. “But – would you mind staying?”


“I could use some company.”

Regulus quirked an eyebrow at him. “Isn’t that what your book is for?”

Snape bit his lip, beginning to fidget nervously. “Do you want to know more secrets or not?”

Regulus considered this. It was a lovely day, but it would be lovely for a while longer, and he didn’t have to go to class again until Herbology in the late afternoon. He didn’t know why Snape hadn’t been invited to the Slug Club, but he saw no problem with taking advantage of it.

“Yeah, sure,” he said, sitting back down. “Let’s start from the beginning, shall we?”


“I can’t believe you’ve started studying already,” Remus said, glancing over at Lily as the two of them emerged onto the grounds, the afternoon sunlight causing their badges to flash together. “You are aware that exams aren’t until the end of term, right?”

“Of course I’m aware. I made up the studying schedule,” Lily said, grinning at him. “It just seems like we have so much material to cover. I don’t know how I’m going to learn it all, even with you, Ellery and Celestina helping, unless I start very far in advance.”

“You’re probably right,” Remus said. “I was just hoping to be able to spend a few more long, lazy days in the sunshine before I had to move into the library.”

“Oh, it won’t be that bad,” Lily responded. “We can go to Hogsmeade and study over Butterbeer.”

“Somehow I don’t think that will make for a good combination,” Remus said, glancing over at the lake. Suddenly, he stopped, staring ahead of him. Lily paused as well, following his line of sight, and finally spotting Sirius and James as they headed in the direction of a nearby tree.

“Padfoot! Prongs!” Remus cried, having forgotten his cover story from the previous night and bolting down the shallow hill toward his friends. Behind him, Lily followed, watching in horror as Sirius pushed her former best friend down onto his back in the grass, spilling his vial of ink. As she approached, she gently shoved the person ahead of her out of her way, looking up to see that it was the boy from Slughorn’s party. He seemed like he wasn’t sure what, if anything, to do.

“Snivelly, I’m telling you, you would think that someone would learn after having James here remove their trousers in a public arena,” Sirius said, grabbing the Potions textbook and letting it hang open in the air before him. “Come on, James, let’s count the poisons he’s marked…”

“Give that BACK!” Snape cried, reaching for the book and falling miserably short.

“Remus!” Lily said desperately, grabbing at his arm. “Wait… do something! Stop them!”

Remus attempted to grab for the book as well. “Why has it got to be me?”

“You’re a Prefect!”

“Lily,” Remus said, sounding slightly annoyed. “You’re a Prefect, too.”

Just then, Snape got hold of the book, and he accidentally hit himself in the nose with it in his desperate bid to return it safely into his own hands. Blood spurted from the wound, dripping down from his nostrils and dirtying the front of his white shirt and Slytherin tie. Without thinking, Lily grabbed his arm and pulled him away from the scene, bringing him to a halt in the grass a few feet away from the small crowd of students who had gathered to witness the event. As she let go, she noticed that Regulus had taken the other arm, helping her make the journey.

“Thanks,” he said shortly, as if she had simply opened a door for him.

“Lily!” Remus cried, and she looked over to see him trying his best to keep James and Sirius from gawking at the damage they’d caused. She frowned deeply, moving over to them and jabbing her finger in Sirius’s chest. “Detention for both of you. I’ll find out when and where.”

“But I didn’t even do anything!” James protested.

“You—” Lily began, but it was true, he hadn’t. “You could have stopped him, you know.”

Sirius looked like he was about to call her a very ugly name, but then he was moving along with Remus and James back toward the castle, having decided it was best to leave her alone for now. She turned away, letting the crowd disperse before she moved back over to look at the victim. Regulus had balled up his robe and given it to him to press against his nose, and the bleeding appeared to have been reduced considerably. Unfortunately, Snape had already passed out.

“Good thinking,” she said softly, gesturing to the robe.

“If there’s no evidence, he can’t really get detention,” Regulus replied.

“I should give it to him,” she replied.

“Why?” Regulus frowned.

“I gave it to those two. He participated in the fight. He inflicted his own wound, even.”

“I’ll bet this isn’t his first broken nose,” Regulus said. “Can’t you just let it go, just this once?”

Lily sighed, glancing down at him. Regulus watched her, surprised to find himself smiling. Just then, Snape began to stir. Before he could open his eyes, Lily had vanished into the castle.


It was waiting patiently for Lily when she entered the Great Hall for dinner that evening, propped up politely on her empty dinner plate, taking up the space for her vegetables. She sat down, having intended to eat alone and focus on re-reading the most recent chapter in her Charms textbook in order to prepare for her study session with the girls and Remus afterwards. But the tiny slip of parchment, with its message in neat, practiced script, caught her attention.

Meet me at the Quidditch Pitch at nine tonight. Come alone.

She stared at it for a moment, her eyes tracing over the careful loops and perfectly spaced letters as she tried to decipher their meaning. She didn’t recognize the author’s handwriting; it was far too legible to have come from Severus, and James’s notes had always seemed more hurried. The words seemed threatening, but the tone was unusual, causing little apprehension for her. In fact, she felt curious, the girlish notion crossing her mind that she might have a secret admirer. If so, Lily, he’s quite rude, she imagined Celestina saying, even as a glint danced within her dark eyes.

Lily folded up the paper, thought for a moment, and made a note to end her study session early.


Author’s Note:

Welcome back, readers! I hope this new chapter was worth the wait :)

First of all, I’m indebted to the HP Wiki for giving me a quick chemistry lesson. I haven’t taken the Herbicide Potion recipe verbatim, but I did borrow heavily from the Wiki.

Secondly, I’m aware that canon does not state that Lily Evans was ever a Prefect, merely that she was Head Girl. I’m also aware that being a Prefect is not a prerequisite for being Head Girl, but I felt like it would make sense that the future Head Girl would be a Prefect, and I also felt like becoming a Prefect would fit with Lily’s personality, so I went with my creative choice and made her one. I do think most of the story fits into canon okay, though.

Thank you for your continued support! As always, anything you recognize as J.K. Rowling’s work belongs to her, not me. Please review, and stay tuned for chapter six!