The first time she sees him is when she drags Severus away from the group of Slytherins he's begun hanging around. She doesn't know who he is yet, but she sees him looking at her with curious eyes; that alone would be enough to tell her he's new, if the fact that she didn't recognise his face hadn't given him away.

He's not the only first year amongst the group, but he's the only one who draws her attention. The others don't look at her when she approaches, and seem to accept Severus' leaving with relative ease (unlike their older housemates, who she knew dislike her for her blood status). But not him – he watched, with those dark, unreadable eyes.

She finds out later from Sev that he is Regulus Black, Sirius' more traditional, conforming brother. It explains why he looks familiar, and even why he manages such a composed and mysterious appearance at the tender age of eleven, but it doesn't explain why he seems to be such an enigma.

She doesn't think much more of him after that. He becomes just another one of Sev's no-good friends, albeit one who watches her silently and (if she's completely honest with herself) a little creepily. There is one time in second year when she rounds a corner to find him and Sirius in heated conversation; shouted comments that are disguised as whispers, for privacy's sake, and both parties fall silent when they see her. She wishes she'd caught a sentence or two, and then inwardly scolds herself for being nosy. The Black family disputes are none of her business.

She nods to them and strides past, but as she walks away she can't help straining an ear in the hope that she'll catch a snippet.

In fourth year, she's invited into the Slug Club. It was an honour not extended to Sev or any of her other Gryffindor friends and she feels helpless and alone without someone familiar by her side. To her surprise, he's there, looking as out of place as she feels despite the fact he has a conversation partner.

After that, Lily also notices a fifth-year she's on friendly terms with, but it is Regulus she gravitates towards.

He sees her and lifts his head a little, in that aristocratic manner she's seen his brother do a thousand times. It irks her just as much.

"You're Severus' muggle-born… acquaintance, aren't you?" he says by way of greeting. He draws himself up so that his stance is straight and proud, and with only a small amount of surprise, Lily sees that he is the same height as her, despite the year's difference in their ages.

"Sev's my friend," she says pointedly. "And clearly I have better manners than you, despite my blood status. At least my mother taught me to greet another person before firing off thinly-veiled insults."

His dark eyes flash with what was either annoyance or amusement. Or quite possibly a mixture of both. "Who was insulting anyone?" he asks smoothly. "I was just ascertaining who you were."

"You might have said muggle-born," Lily said surely, "but you and I both know that you meant mudblood."

She can only assume that the stress of the week had gotten to her, or that the night was making her bold, because it was something she would never have said if the situation had been different. She wouldn't have been surprised if he walks off or retorts nastily; while his greeting had been coolly condescending, her reply had been nothing short of rude. Already she is feeling ashamed of her words, and her quick temper.

But no retort is forthcoming. Instead, his face breaks into a genuine smile and a laugh bubbles from his mouth. Lily realises it is the first time she's seen him do either of those things.

"Aren't you a fierce little lion?" he comments, a statement that should have rightfully offended Lily. Surprisingly, it didn't. "And you're right. We Slytherins are all the same. But you don't say such a controversial word in polite – and, more importantly – liberal company."

"If my existence offends you so, then why do you stand talking to me?" she asks brazenly.

"I'm curious."

"Curious of what?"

"Curious of what… they see in the rest of you."

"If you're going to be all cryptic, I shan't bother talking to you," Lily informs him tartly, annoyed by both his non-answers and the mirth dancing in his eyes – mirth at her lack of understanding, she wrongly misinterprets.

"My apologies," he says, and bows mockingly. "By 'they' I mean Severus and my dear brother. By 'rest of you', I mean people who aren't purebloods and don't gain them social standing or favours of the political kind."

"There are other things in life than blood and politics," Lily tells him.

"Spoken as a true muggle-born," he sighs. "When you're raised as a pureblood, there is nothing else."

"Seems like a pretty dull life," Lily comments, ignoring the chills running down her spine at his words.

"You'd be surprised."

"So do you have some special talent?" she asks.

"Pardon?" He's confused, and Lily mentally gives herself a point for catching him off guard.

"This party," Lily says, gesturing around them. "Everyone here is good at something, or everything, or is related to someone famous. What gives you the golden ticket to Slughorn's gates?"

"I'm a Black," he states simply. "That's a ticket to pretty much anywhere."

"I don't see your brother around," Lily says. She doesn't need to see; he and Potter aren't exactly the walking definition of 'quiet'. There are literally times when you can hear them a mile off.

"He's not much of a Black," Regulus drawls. "Although that's not the reason he doesn't attend these events. He was invited back in his first year, same as I was. However, two of his friends was refused the same invitation, so in a fit of stupidity and loyalty, he declined it on those grounds."

"Stupidity and loyalty are not the same things," Lily said.

"They are in this case. Loyalty to one's family is rarely stupid," Regulus drawls. "But passing up an invitation to a club where you can rub shoulders with some of the futures most influential people for the friendship of halfbloods and blood-traitors is certainly idiotic."

"Why do you do that?" she demands.

"Do what?"

"Reel off pureblood propaganda like you're a voice recording. Your voice even changes slightly when you do it."

"Does it? I've never noticed."

He never properly answers that question, because Slughorn chooses that moment to socialise with them, and afterwards they don't get a chance to chat before the party is over and it is time for them to be going. Lily finds herself searching for Regulus as they walk out, with some half-formed notion of continuing their conversation on the way back to the dormitories, but he is already gone.

Alice is invited to the next party, as Slughorn somehow discovered her aptitude for Defence Against The Dark Arts. It would seem strange to leave her in favour for a conversation with Regulus, and for a reason she can't explain, Lily doesn't really want to include her friend in their dance of words. So she sticks by Alice's side and makes small talk with those she neither knows nor likes, and she watches Regulus from afar.

He has his friends too, milling about him, but he still manages to look alone. She wonders where all those older boys were last time; she wonders if he deliberately left them so he could talk to her.

By this point, her relationship with Severus was deteriorating rapidly; while it was clear that he still wanted her friendship (and perhaps more if she'd allow it), it was equally apparent that he would not forsake the allies he'd made in Slytherin – all of whom, it was unanimously agreed upon by Lily's friends, were shady characters at best.

In her first years at Hogwarts, Lily had stood by while Severus formed friendships and alliances with that unsavoury lot. After all, they were his housemates where she was not, and they were just children. While they weren't the sort of people Lily would have associated with, she hoped for Severus' sake that, over the years, they'd grow up to be less… dark.

But Lily had ears, and she had eyes. She knew already, like much of the school did, that something dark was approaching Britain out in the real world, and it was approaching with great speed. Mentions of 'Death Eaters' were becoming more frequent in the paper, and people in Hogsmeade muttered about a war of the likes Britain hasn't seen for centuries. Lily knows that it's coming, and she'd like Sev to be on the right side when it does.

It isn't until her fifth year, dawning dark and dangerous with shadows of deaths and disappearances looming over the returns of the older students, that Lily really begins to get to know Regulus. It is purely an accident that she runs into him, although she'd later wonder whether what forms between them would have happened regardless of if she'd found him in that hidden passageway or not.

It's a surprise to see him there; so much so that she almost stands on him. She uses this shortcut often; it's a convenient way to get to charms without having to shove through crowds, and since she's returning to her dormitory from prefect duties, she'd thought it would be quicker.

She doesn't count on Regulus, sitting on the floor with his knees drawn up to his chin and three large bottles of firewhiskey beside him. Only two are completely full.

She should give him a detention, she knows, or report him to a teacher for drinking and being up after curfew. At the very least she should walk away. She should, but she doesn't.

Perhaps it's because his eyes are red, a give-away that he's been crying. Perhaps it's because he makes such a dejected figure, huddled there as he is. Or perhaps it's because she's always been drawn to him, even in the very beginning, and she's only just now ceasing to deny it.

No matter the reason, she sits beside him without saying a word. He wipes and hand angrily across his eyes and takes another swig of the bottle. He looks at it as though it's personally offended him, and then hands it to her, his eyes fixed on the far wall.

She's never had firewhiskey before, but she takes a tentative sip… and chokes. It burns the inside of her mouth, and when she swallows it feels like her throat is on fire. She coughs and splutters, almost dropping the bottle. As she curves her body over, she feels a strong hand pat her on the back, and another sneaks around to rescue the vile liquid from her loose grasp.

"That stuff's horrid!" she exclaims.

Regulus manages a grin. "I know," he says, taking a swig of it. "Want some more?"

This time, she doesn't cough nearly as much.

"My brother left home over the summer," he tells her, after she's finished almost choking on the burning in her throat.

"I know," she says. Remus is her fellow prefect and, more importantly, her friend. He usually keeps her up to date on what's happening amongst the 'Marauders', their pet-nickname for themselves.

He's also very good at warning her when James is about to ask her out in some extraordinarily public manner.

"I want to say he ran away, but my parents drove him off," Regulus continues. "He would have left years ago, but he didn't want to leave me on my own there."

"Is it that bad?" Lily asks.

"It was for him," Regulus says. "He was the white sheep, and he never got along with my parents. It's different for me, but…," he takes another sip, "I think he wanted to keep me on his side. On the muggle side."

"On the side that isn't Voldemort's," Lily states, rather than asks.

Regulus winces as the name, as so many people were wont to do these days. "Yeah," he says, not meeting her eyes. "But it got too much. And I think he's given up on me."

"I'm sure that's not the case," Lily says.

Regulus laughs, a bitter harsh sound that is more a bark than a sound of amusement. "If he hasn't given up by now, then he should. I've only got three more years of this place, and then I'll be a Death Eater."

Lily shivers, although it isn't cold. "You don't have to be, you know. You could choose a different path."

"One like my dear brother, you mean?" Regulus asks derisively. "Fighting for good, the champion of muggle justice?"

"You could do nothing," Lily says reasonably. "If you become a Death Eater, you'll kill people. You'll torture people. You'll tear apart families. If you don't die in your first year, Voldemort might be strong enough to tear down a government, and you'll be responsible for throwing a country into turmoil."

"The people deserve it," Regulus whispers. "This government is corrupt and wrong. And I'll be rewarded." His voice was uncertain, though.

"Rewarded with what?" Lily asks roughly. "Death and destruction in return for what? How can gold or power possibly be worth killing for?"

"I'll be a hero," Regulus whispers, and she suddenly glimpses the scared fourteen-year-old boy he really is.

"To most people, you'll be a villain," Lily tells him. "To the families of those you kill, you'll be the man who destroyed their happiness. And there will be a lot of families."

"That's the price of power," Regulus whispers.

"There are other ways to get power," Lily says. "Better ways. And power isn't all there is in this world."

"Not if you're a Black."

"Even if you're a Black," Lily insists. Then they reach the bottom of the first bottle, and Lily tells him not to open another.

"Go to bed," she orders. "And drink some water. And when you wake up with a pounding head in the morning, remember that it's a terrible idea to drink almost an entire bottle of firewhiskey by yourself."

"It was already half-empty," Regulus mutters, but does as she says.

The next day, she sees him alone in the library, and she asks him how his head is. Things spiral from there.

She learns more about him then she could ever have dreamed. They talk for hours and hours most days, to a point where the week seems strange if she's only spoken to Regulus on four occaisions. They meet… not exactly in secret, because it's often in the library where anyone could see them, but if one of them has company then it is an unspoken agreement that the other won't approach.

That is all that is unspoken, though. The rest of their lives are discussed at great length, to the point where Lily actually feels closer to Regulus than she does to Sev, who is becoming more and more of a prick. She's spending more time with Regulus, too – Reg, she sometimes thinks of him, although she never says it. And she finds that 'Sev' is quickly becoming 'Severus' in her mind.

Regulus tells her what it's like at home, and the expectations that are placed on him now that Sirius has left. Sometimes he cries at the helplessness of his life; the only way forwards that he can see is becoming a Death Eater; his father talks of little else, like it's already decided, although no one asked him. Lily tries to tell him, tries to show him, that he does have a choice, but she doesn't think she's very successful.

"Please," she begs him, "there are other ways to keep your parents happy. You're better than this. I know you are." Sometimes she'll tell him, "You're not as evil as you think," or a variation thereof, but those are only ever the times when she's run out of arguments. This isn't a fairytale. He doesn't think he's evil. To him, it's a combination of being right and having no other choice in the matter.

Usually, he just shrugs, regardless of what she says.

And Lily confides in him in return. She tells him about how Petunia wouldn't speak to her when she went home for Easter, and how Severus is drawing further and further away from her, into the depths of the Death Eater group in Slytherin and into his hatred for Potter and Black. She muses, at one point, how strange it is to be telling all this to the boy who insists he will be Death Eater, about her friend of many years who might become a Death Eater.

Then comes the summer between fifth and sixth year. Lily writes to all her friends to pass the time; there isn't much else to do with Petunia not talking to her. Well, all her friends except Regulus. She doesn't want to get him in trouble with his parents, and he doesn't write to her either.

When she gets back, though, things are the same as ever. Their conversations become the highpoint of her week; soon they are meeting daily in the hidden passage where they first drank firewhiskey.

In the third term, she finally does what she's been wanting to for a while now, and kisses him. He's surprised, at first, but kisses back.

The hidden passageway becomes their secret rendezvous point; a space just for them, where they can be together and not have to hide. It's where they talk and kiss and sometimes go further. A month later, it's where they give each other their virginities.

It is with a sense of foreboding that Lily realises she's fallen in love, which would usually be a good thing, but the person she's fallen for is on the wrong side. Sometimes she's sure he loves her too, but she never manages to fool herself that he loves her enough to rebel against his family and his heritage. She doesn't like to think about it, and neither of them ever brings it up any more.

They spend a blissful few months together, with their happiness built on secrets and imaginings and avoiding the big questions. Lily knows it can't last, but she doesn't admit it to herself. Sometimes she daydreams of a world in which she and Regulus could be together properly. She wants to hold his hand as they walk down corridors, and act like all of their other friends who are in love.

She daydreams that he'll change sides for her.

All too soon, the next lot of summer holidays arrive. There are still no letters passed between them, but Lily spends most of the time thinking about him, and she suspects he thinks of her too.

It was a torturously long time, but soon they are back at school. To her horror, Potter is Head Boy, and she is Head Girl. She thinks there must be some sort of mistake, because he wasn't even a prefect, but the teacher seems to accept him into the prefect carriage without a problem. Regulus is there too, of course, and their eyes meet when no one is looking. Something flashes between them and she knows they are the same as ever.

She's too busy on the first night to meet up with him, but on the second night she manages to get to the secret passage. He is already there, and they fall together. Afterwards, he caresses her naked skin and tells her that he missed her, that he wishes they never had to be apart, and he confesses he's in love with her.

She wants to ask whether he loves her enough, and that if he never wants them to be apart, why is he making it so they have no choice but to separate? She wants to say that she's a mudblood, and if he truly loves her he'll leave his Death Eater friends and tell his family where to stick it. But she doesn't. She just says, "I love you too."

It soon becomes clear that their relationship is not what it was. There is an underlying awkwardness that Lily puts down to her resentment over his life choices, and they are now both so busy studying for NEWTS that their daily meetings become weekly. The papers become darker, and the war is now being openly fought, both by the ministry and by the independent group calling themselves "the Order of the Phoenix" (who, to be honest, seem to be doing a much better job than the aurors). It's a subject that neither of them ever brings up, because each person knows what the other will say.

What's more, her Head Girl duties are forcing her to become closer and closer to Potter, who, to her frustration, is not as annoying as he once was. His head seems to have shrunk about twenty sizes over the summer, and while his courtesy does not completely extend to Severus (who Lily barely sees anymore, anyway) he has almost stopped the pranks and no longer hexes Slytherins for the fun of it. Well, not when she can see, at least.

He's asked her out numerous times before, but now he begins to… court her, in a much more subtle fashion. He seems to be close, always, and he'll ask to carry her books if he catches her returning from the library. They share actual conversations now, in which he talks about sensible things (by which she means things that aren't pranks), and the war quickly becomes a favourite topic between them. They share the same views, and she's been too afraid to talk about it with Regulus for a long time. It's nice to not shy away from that topic.

She still sees Regulus sometimes, although they aren't what they were anymore. She might have called them 'lovers', once, but now they seem closer to acquaintances-with-benefits.

After the first holidays, James begins to subtly give her presents. She doesn't even realise it's what he's doing, because their exchanges go something like this:

"Hey, Lily, do you like the new butterbeer-flavoured chocolate from Honeydukes? Because someone gave me these for my birthday and I don't really like them."

"I guess they're quite nice…" she says noncommittally.

"Here, have them then," James says, handing them to her. "They'll just go in the bin otherwise."

It isn't until later that she realises that his birthday is months away and that she'd mentioned she liked the new flavour the other day.

He begins to date her in much the same way, by asking her to accompany him and Remus to Hogsmeade. She suspected that one was a set up from the very beginning; mostly because Black, who annoyed her, wasn't there, and Remus, who was Lily's friend, was. It was confirmed when Remus went home after half an hour, claiming he wasn't feeling very well (and Lily knew the full moon was weeks away). She should have made her excuse to leave, too, but she was enjoying herself too much to seriously consider it.

He begins to pay more attention to her after that, and she finds that she's flattered despite herself. Her relationship with Regulus had been secret meetings; they'd never even been on a real date and he'd certainly never tried to woo her.

It does bother her that James doesn't know about Regulus, and she also feels a stab of guilt that she's cheating on him. She reasons that she's only sort of cheating, but she knows deep down that it doesn't make it okay.

She loves Regulus, she really does, but she's finding that she also loves being in a proper relationship. She knows she can't keep up this two-timing. Regulus has probably begun to notice already, and she feels too guilty about keeping him from James.

The next time they meet up, she tells him that it's over.

He takes it better than she expected, in a way, and worse in others. "It's Potter, isn't it?" he asks sourly.

"It's the secrets," she says, avoiding the questions. "I want a relationship that I don't have to hide. I want to be able to talk to my boyfriend about the war and not have him answering from the side of the Death Eaters."

"What if I said that I could do that?"

"Can you?"

"I could try."

"Try? You either can admit to everyone that we're a couple, or you can't. There's no middle ground."

"What if I become a spy? I could join the Death Eaters and give information to you. Could we still be together then?"

She sees why he'd want that. He can keep his parents thinking he was the loyal son, and keep her a secret without losing her. But they still won't be out in the open, and….

"How could I know that you were giving me true information?"

"You'd have to trust me."

"It's asking a lot, to trust a Death Eater."

There is silence, and she knows she's said the wrong thing. "Is that all I am to you now?" he asks. "The enemy?"

"You're the one who wants to have a secret relationship with a person he'd be persecuting!" she exclaims. "I didn't ask for this! It's not like I can switch sides, can I? And clearly this isn't going to work if we're supposed to be enemies."

"So that's that, then?" he asks.

"It seems so," she says, sadly.

He picks up the empty bottles of firewhiskey that are on the floor. There are three of them; the same three as there were when they first came here. They'd emptied them a long time ago, but neither of them had every taken them out. They were evidence that, even though they weren't in the passageway all the time, the place was still theirs.

He reaches the door, and turns back. "You know, I really did love you," he tells her.

"I still love you," she says, fighting back the tears. "But I can't do this anymore."

"If things had been different…" he says.

"We would have been so happy," she tells him, smiling through the tears she couldn't stop from streaming down her cheeks. "So happy."

The door clicks shut behind Regulus, and Lily is alone.

He hears about the prophecy, from Severus Snape of all people. By this point, he's risen far in the ranks of Death Eaters, and he knows the inner workings of the group – although not everyone is aware he knows so much.

He also knows the crushing secret of the Dark Lords power, but he tells no one.

Doubts still riddle his faith; many times he wishes he could just leave, and start a new life somewhere. But the Death Eaters would hunt him down. If only he'd taken Lily's offer that day in their passageway. He could have had everything.

It's like a knife to his heart, the news that Lily and her family are being hunted by Voldemort. "They're protected," Severus says, the only words after 'he's going to kill them all' that gets past the buzzing in Regulus' ears. Protected, but only for now, he thinks. He knows as well as anyone that there's going to be no quick end to this war, particularly not with the Horcrux that the Dark Lord had made.

That night, he takes Kreacher to the cave, knowing he won't come back. He gives his life so Kreacher can live for three reasons. The first is that he really does like the elf; he was the one good thing about Grimmauld Place once Sirius had gone.

The second reason was that she would have approved of it, giving his life so another may live.

The third reason was that it was a much better death than the one Voldemort would have given him when he was found out.

I did have a choice, he thinks to her, as cold, dead hands clutch at his drowning body. In the end, I chose the side you wanted me to pick. I just hope it's in time to save you.