It was mostly by accident that I overheard Bellatrix laughing about the spy they'd acquired among James and his mates. I didn't want to think about the things they'd done to the poor bugger to make him turn. And it was sort of by accident that I found out Sirius was on the hit list, as one of the people who might be able to give up information about James if tortured. I didn't want to imagine the things they'd do to him, either. It was completely by accident that I found out James had a wife and son, which made me sad. But none of those things were what made me decide to do it.

I'll tell you what was.

Because I was still a student, I hadn't seen much action. Father had died, but by that time, Sirius was out of school and I had no way to contact him, so I hadn't seen him either. He didn't come to the funeral, of course. I was working harder than ever to comfort poor Mother who was completely beside herself and spent half of her time ranting or talking to my absent brother or her dead husband. And in a bout of devoted concentration for her sake, I'd drummed up a little plot among the parents of some Hufflepuffs who sat near me in class. I was pleased to pass this along, as it seemed like a pretty good find, and I'd be able to tell Mother I'd finally made an impression.

It took two weeks for me to hear the news. The two Hufflepuff girls were taken out during class one day. Both of their parents had been killed, brutally, so I heard. No one knew how the Death Eaters had found out, and everyone tried to comfort their distraught schoolmates, except for me. I lay in bed and heard the sound of the one girl's sobbing in my mind long after everyone else had fallen asleep. I sat in class and stared at the empty seat of the other girl—she'd fled home to her grandparents—instead of paying attention to the day's lecture.

That's when I realized what I was doing. Killing. I was sending people to their graves, orphaning children, betraying my companions. And that's when I knew that the spy who was working on Sirius' mate, James, would end up the same way. People would die. I was part of a network of killers who would stop at nothing. Who gave a damn if that Hufflepuff girl was a mudblood? It didn't make her tears affect me any less. I wanted out.

Of course, there was no way to do that without incurring the wrath of the Dark Lord. And there was absolutely nowhere I could go. I couldn't bear to tell anyone about what I'd done, not for anything. Just imagining confessing my crimes made my blood run cold. And none of those rebels who fought against us would dream of taking me in.

Except maybe one.

I hadn't seen Sirius since his graduation in 1978, three years ago, and I afraid of what might happen. But I had to go.

December, 1980
Sirius' Flat, London

I knocked on his door with a whole bloody lot of trepidation. And the wait was so long, I almost decided he wasn't home and turned to leave. But I didn't. I waited. And eventually he answered.

He looked different. Not really different, mind you. Just different enough to make me hesitate. His chin was dotted with dark stubble as if he hadn't shaved that morning, and his long, black hair fell free, brushing his shoulders. He had a quill in one hand, and the sleeves of his loose-fitting shirt were turned up to the elbows. Mother would have scolded him instantly, told him to clean himself up.

But most of all he just looked older. Still beautiful, and still as sharp-featured and smooth-skinned as ever. But older. Around the eyes, especially.

I didn't have to feel bad about giving him a once-over, because he started and stared shamelessly on sight of me. At last he said hoarsely, "Regulus?" He still stood in the doorway, leaning on the frame. I decided to assume he hadn't invited me in out of shock.

"I know it's a bit unexpected, but I wanted to talk to you," I began, staring at his front steps. He didn't have a welcome mat, I noticed.

"A bit?" he repeated incredulously. "Where the hell did you come from?" Almost immediately his brows furrowed and his eyes darkened. "If this is some bloody propaganda mission or something, you can shove it up your arse."

I looked up defiantly. "It's not," I assured him. "Actually, I just wanted to speak to you, brother to brother."

Well, that really gave him a fit. He didn't stop laughing for almost a minute. "Brother to brother," he mimicked, eyes wide with mirth and surprise. "Please, Reggie, we haven't spoken in years. We hardly ever spoke even as kids. Don't you think this is a bit late to be starting?"

He pronounced 'Reggie' with too much intonation, almost as if mocking the old childhood nickname. I was upset, but I didn't want him to see me cry, so I got angry instead. A typical Black response. "Maybe if you'd ever bothered to listen!" I exclaimed, and it got his attention. He sobered up in a second, but his frown suggested I'd hit a nerve and wasn't likely to get a warm reception.

"I just… well… I'm having some problems," I said. It was harder to get out than I had expected. And all the time I was terrified of Sirius' response, I was even more terrified that the Dark Lord might somehow get wind of my betrayal.

But Sirius, to my delight, looked concerned and motioned for me to follow him into the flat. It was sparsely decorated, but with class. Everything was modern and rather muggle-ish. Almost as if he'd wanted to make it the opposite of our elegant, old childhood home. Sirius nodded at me to sit down as he swung his legs over a chair and faced me. He put his quill down on an end table on his right.

I really wanted him to understand everything, which is why I tried to start at the beginning. It was a big mistake. "Well, Mum's been having a lot of trouble, ever since you left…"

Instantly his expression turned stormy and my brother gave me the fiercest scowl he'd ever given. "I don't want to hear about Mum," he snapped. "And I don't want to hear about her pathetic problems, or how hard she took my leaving. Getting the hell out of there was the best thing I ever did."

This was already unbearably awkward. "Right," I said weakly. "Well, I… er… I wanted to do something…" My wandering gaze fell on a baby rattle nestled near a sofa cushion across the room. I wasn't one hundred percent sure Sirius hadn't sired a child somewhere along the way, but I didn't really think so. I wondered if it belonged to his mate's kid. It bolstered my courage. Surely even my surly, proud brother cared about family, right? "I wanted to do something good for the family," I explained at last.

"So you joined the dark wizards," Sirius finished for me in a dark tone. "Yes, I heard. Bellatrix told me." Before I could question him with indignation, he nodded and went on. "She spared no expense rubbing in the fact that my baby brother was now my mortal enemy. Well, congratulations, fool! I hope you're happy!"

"But I'm not!" I stood up from my chair in a rush of swirling robes. In a fit of emotion, I went on without pausing to think. "It's not what I thought it would be. I thought I would be clever and bring lots of honor to the family, but the things they're asking me to do… I don't get any help from Bellatrix or Narcissa and Mum's just as miserable as ever. Nothing's ever changed! I feel like I'm living in fear all the time, but nothing I do makes anything get better!" I was getting close to hysterical tears. "And I just know they're going to send me on field missions as soon as they can, and I don't want to go! I'm not any good at hexes, and this spying business just makes me feel awful. I tried to make friends with the other young members, but they're not really that much like me and I always feel like an outcast! I'm afraid of the Dark Lord, and I'm afraid of getting caught! My life is miserable!"

I had to pause eventually to get breath, and to calm my shaking shoulders. To my horror, Sirius' expression had remained blank and stony throughout my entire speech. I couldn't tell if I'd gotten through to him at all. At last he asked in an odd voice, choked with concern, "Are they giving you trouble, Regulus? Are you in danger?"

I shook my head with a sigh and reclaimed my seat. "No, I'm not in danger. My job's pretty easy and safe. I don't think anyone even suspects me."

There was a tense silence. Sirius looked me straight in the eyes, his grey pupils providing the only warmth in his face. "Then what do you want?" he demanded coldly.

I wasn't sure what to say. I gave him a stare of incomprehension. Sirius' lips grew firm and grim. "Surely you didn't come all the way here just to complain to me about how things didn't go your way," he said. "So what do you want me to do?"

I really wanted to beg him to take me in, to hide me. I wanted to explain that I was through with the Death Eaters, that I had never agreed with them really and that I just wanted to be his brother and nothing more and let's end this feud! But I didn't. I didn't because it would have killed my mother. If I abandoned her and went over to Sirius' side, after all these years, she would never recover. Besides, father was dead and she was all alone with no one but her house elf to care for her. I couldn't just turn my back on her and all my family as though they didn't matter and hide in Sirius' closet for the next decade. I just couldn't. Besides, it was common knowledge that deserters who couldn't be found were often ferreted out by having their loved ones killed one by one, slowly and painfully.

It was a terrible stalemate. If I asked Sirius for help, Mother would be left defenseless. If I didn't ask, I mightmeet some horrible fate.There was only one solution I could see. Taking a deep breath, I plunged in.

"Come back and see Mum," I said. "Make up with her. Then we can all go away together, away from the Death Eaters,and put all this behind us."

His reaction, as I might have expected, was bad. In a horrible, icy voice, he rasped, "And by 'all this' I suppose you mean my life, and everything in it. You want me to come crawling back and pretend as though I don't believe in the things I've been working for all this time? And after that you want me to hide the two of you like rabbits in a bloody hole, so that you can avoid living with the consequences you've brought upon yourselves, is that it?"

I was so miserable, I couldn't even answer.

"Well, forget it, Regulus." My brother stood. "If that's what you want, you can run crying to someone else. I'm never going back to her, ever, because I'm not the least bit sorry." Now he was pointing to the door. "I asked you for help once, brother, and you turned me away and sided with her. If you're so damned attached to that hag, you can get out of my house right now!"

His voice left no room for questioning. And I didn't even feel up to it, if it had. All thought of warning Sirius about his mate's predicament and the spy fled my mind. Anything I had been going to say to prove my sincerity evaporated on my lips. Within seconds, Sirius had turned his back on me, picked up his quill, and stalked into an adjacent room, as if I were no more important or worrisome than a shadow.

And to my dishonor, I didn't stay and fight him. I didn't try to convince him otherwise. I turned around and left.