Previously in the Darklyverse: Believing Remus was the Death Eater spy, Sirius intended to switch places and make Peter the Potters' new Secret-Keeper.

xx

Back up—

October 24th, 1981: Sirius Black

(the moment of divergence)

There are a dozen things on Sirius's mind when he knocks on the door to Peter and Emmeline's flat, but the dominant one is hope: hope that Lily and James's safety will be more secure in Peter's hands than it is right now in Sirius's. If Remus is the spy—if Remus gives away to Voldemort the fact that Sirius is the Potters' Secret-Keeper—the Death Eaters won't be able to wrench the secret out of Sirius, but if they kill Sirius, they'll certainly be able to get it out of Remus when the Fidelius Charm transfers to him and every other member of the Order. No one will think to go after quiet, thoughtful, meek Peter as the guardian of the Potters' location, and as long as Peter doesn't get himself killed in combat, James and Lily will be safe under him for a long, long time.

It's Emmeline who answers the door, still in her pajamas and nursing a cup of tea. "Oh, hi, Sirius," she says as she wraps a robe around herself clumsily with her free hand after it lets go of the door. "We didn't get scheduled for overtime at Scrivenshaft's or anything, did we?"

"What? Oh, no," says Sirius with a chuckle. "Peter's home, right? I just need to talk to him for a few minutes."

"Yeah, he's in the bedroom. I'll give you both some room to talk."

"Thanks, Em."

"I think I'll make some breakfast. Let me know if you want any flapjacks while you're here," she calls at his retreating figure as he passes the living room and kitchen and squeezes down the narrow hall that leads past the spare and into Em and Peter's bedroom.

Peter looks anxious, but that's nothing new, with how many of their number have died in the last several months. Sirius himself feels like there's a cloud of grief and apprehension hanging over him everywhere he goes. As Peter sits up a little in bed and un-plasters his hair from his sweaty forehead, Sirius sits down on the edge of the bed next to him and stashes his wand in his pocket. "Hey, man," he says, and his own voice sounds scratchy and foreign, like someone has taken a hatchet to his vocal cords and severed his ability to speak like a normal human being.

"What's up?" asks Peter fervently. "Is everyone okay? Did something happen? It's so early."

"Nothing happened. Well… nothing happened, but I wanted to run something by you."

"Sure." Peter sounds unsure, like he doesn't know what awful proposition Sirius is going to hurtle at him, and can Sirius blame him, in these times?

"It's about Lily and James," Sirius says in a rush. Peter stares blankly back at him. "I want you to replace me as their Secret-Keeper."

Peter's mouth falls open a little bit, and his eyes start to dart here, there, all around the room at anything but Sirius—but Peter doesn't speak. "I'm too big of a target," Sirius continues. "If they go after me and kill me and the spy becomes one of the Secret-Keepers…"

Peter doesn't answer.

"They'll be safer with you," Sirius says now. "You don't look the part as much as I do."

Peter doesn't answer.

"I don't mean that in a bad way. I'm not saying you're any less Prongs's friend than I am, or that you're not as brave, or even that other people think you're not as brave. If it'll keep Harry safe—"

"I can't," Peter finally says. He's gone all pink in the face, and it looks like it's costing him something to say this.

"But—this is about protecting our friends. I thought that you—"

"I can't," says Peter heavily, raising his eyes reluctantly to meet Sirius's, "because it's me, Padfoot. It's me."

"What's you?" Something starts to register in the back of Sirius's mind, but he doesn't let it in enough to identify it. It can't be. This is Peter. "What are you that you can't protect them?"

And Peter bursts, "It's because I'm the spy!"

And everything goes out of order. His legs go numb; his hands and fingers start to tingle; he sees red and hears a low buzz that gets louder and louder the longer that Sirius sits on that bed staring at Peter like Peter's just rocked his whole world, and he has, hasn't he? The spy isn't Remus. It's not Remus. It's Peter.

Oh, god—and Sirius realizes that he's been blaming, holding at arm's length, the wrong person this whole time. Remus, whom he loved. Remus, whom he loves.

"How?" Sirius breathes.

"Because they threatened me," Peter whispers, turning steadily redder in the face. "Because they threatened all of you. Because they burned down Mary's house and poisoned Moony and started to cut off my toes. I thought it was harmless, Padfoot, just giving them a couple of details, a couple of names, but then everything started to spiral out of control and I got in too deep. I thought I couldn't tell anyone without making you hate me—"

"As we should," says Sirius. Something seems to snap inside of him, and the red edge to his vision is getting darker.

"Padfoot, we're losing. You get that, right? We're going to lose anyway—we're all going to die anyway—but if I could just—"

"Save yourself?" spits Sirius. His voice is rising. "And throw everyone else who loves you, who is fighting for a better world, under the bus?"

"Oh, so now you love me?" says Peter. His voice is getting louder, too, verging on hysteria. "You spent years shutting me out, replacing me with Lily, and now you say you love me? I'm so sick of being treated like an afterthought! I—"

"You know what I'm sick of, Wormtail? I'm sick of my friends dying. How many of those deaths are you responsible for, huh? How much of it is your fault that the Death Eaters have gone on an Order of the Phoenix killing spree these last few months?"

The door creaks open. Sirius startles; he'd completely forgotten that he and Peter aren't alone in the flat. "What's going on?" asks Emmeline. "I heard—"

"I can't believe you," Sirius carries on as if he can't hear her. "I can't believe you. How long—?"

"It was never supposed to go this far," says Peter with a pleading note.

"How long, Peter?"

"Since—since the end of sixth year," Peter says.

"This whole time," Sirius mutters. "This whole time, you've been feeding them information."

Em interrupts, "Feeding who information? Peter—"

Sirius doesn't really know how it happens. One second, he's sitting next to Peter on the bed, his wand in his pocket, and the next—he doesn't remember pulling out his wand, for one thing. He must think the incantation, because he doesn't remember saying Incarcerous, either, but the next thing Sirius knows, Peter is bound in ropes on the edge of the bed, breathing hard and squirming.

"Sirius!" Em cries. "Sirius, what—?"

"He's the spy, Em," says Sirius heavily. "Don't let him get away."

But Peter is too quick for him. With an almighty wrench, he gets his hand on his wand and transforms; the ropes collapse around him onto the mattress as Wormtail scuttles away. Sirius points his wand and bellows, "Stupefy!" once, then twice, but he misses as Wormtail scurries through the doorway, down the hall, and—Sirius imagines—through the open window in the living room and outdoors.

"Sirius," says Em again, and she's crying by now. Sirius can hear it in her voice—can hear, too, the rustling sound she makes when she mops her eyes with her robe sleeve.

"Dammit," says Sirius. "Goddammit. He could be anywhere by now."

"But how did he—?"

"He's an Animagus. We all are. So that we could be with Remus every full moon, before the Wolfsbane Potion."

"I don't understand," she says now. "How could it be Peter? How could it be Peter without me knowing? How could he do this and not tell—?"

"You and me both, mate," Sirius says. "He was my brother. I thought he was my brother."

And then Sirius breaks down, not in a cry, but in a laugh—a mad, manic laugh that crashes around the room that's far too small to contain his grief.

xx

So it was Peter. Peter. All this time, he's been assuming that Remus was the spy, holding it against him, avoiding him as much as possible, and now he finds out that he's been misdirecting his mistrust and rage all this time. But Sirius can barely register the reality that, now that it isn't Remus, he can apologize to him and try to repair their relationship. It's almost totally drowned out by his horror, disgust, and hurt that Peter has been lying to them—to him—all along.

How much of the Order blood that's been spilled is on Peter's hands? How many lies has he told? When Sirius told him that he suspected Remus as the spy, how deliberately did Peter egg him on in his mistaken belief to take the heat off himself?

Emmeline fixes Sirius a strong cup of tea, but neither of them can stay long. "We have to tell Lily and James first," says Em fervently. "And Dumbledore. He'll probably want to call an emergency meeting."

"I'll tell—I'll tell D—" Sirius tries to say, but he's laughing too hysterically to get the words out. He takes a few deep breaths and downs a couple swigs of tea, trying to get himself under control. "I should tell Dumbledore. I don't know which would be—harder for you, and I know Peter was your…"

"He was everything," Em says quietly. "I just can't believe it. How did he—how could he—?"

In a flash, Sirius remembers back in seventh year the way that Peter was probably one of the only things tethering Emmeline to life. "Hey," he says. "Are you going to be okay? Do you want to stay at my place tonight? Or—you might not want to be around Lockhart that much, and neither do I, actually, but I could stay here instead, if you wanted."

"Oh, I couldn't ask—"

"You're not asking. I'm offering. Honestly, I could use the company, too. I can't be real about this in front of Lockhart, you know?"

Emmeline looks torn, but eventually, she nods. "Yeah, okay. You can take me and Peter's room, and I'll sleep in my old room from before. I don't think I can stand the smell of him right now."

Me, either, Sirius thinks, but not for the same reasons Em is probably thinking. "We're going to be okay," he says instead. "The important thing is that he fessed up before we made him Secret-Keeper so that he could blab their hiding place to Voldemort. Lily and James and Harry could have all been dead within the week, by the time the charm took effect, but they're going to be okay. I don't want you to…"

"I'm not going to try to kill myself again," says Emmeline, rolling her eyes.

But Sirius isn't so sure. "Okay, but if it does come to that, come and get me, okay? He was your boyfriend."

"And he was your best friend. It's not like I'm the only person who cares about Peter. Er—cared about."

He should tell her that it's okay to still care, that she's not crazy just because she can't turn it off without time to process, that she's allowed to mourn, but he's not that good of a man. Now that the shock is wearing off, the buzzing in his head has turned wrathful and enraged. "We should head out. Who else do we need to tell? Remus, Alice—somebody's got to tell Mary—"

He almost tacks Marlene's name onto the list, but, of course, Marlene is dead, and she'll never know what Peter has done. Is Marlene's death Peter's fault, too? Does Sirius have Peter to blame for losing his ex-girlfriend? As if Sirius's feelings about Marlene weren't muddled enough…

The last time he saw her—just minutes before the Death Eaters got to her, mind you—they'd slowly been bridging the gap toward becoming friends, actual friends, or at least that's what Sirius had thought before she kissed him on the cheek and told him… what was it that she said? Something about wanting to have one good memory of them, about loving him even though she didn't understand in what way. He can't remember her exact words—her dying words—and he'll never see her to hear them again, to find out if they can ever get to a place where his feelings for her match her feelings for him. Shit, she pretty much spent the last six years of her life pining over him, even though for most of them their relationship was totally shattered, and now she's never going to have the chance to move on and make something else of her life.

Maybe it's arrogant of Sirius to assume that he was Marlene's whole world. She had her job as a Hit Wizard, after all, and her friendship with Lily and her relationship with her uncle—her father, Sirius corrects himself, though it's still hard to believe that she managed to keep Doc's real identity hidden from all of them for all this time. She had her mum and her siblings, and she had the Order, and she was a whole, entire person outside of Sirius.

But—she loved him. And they couldn't hold it together. And now he's never going to be able to make that equal.

For the millionth time, he just wants to talk to Remus about what's in his head—but this time, he realizes belatedly, he actually can, because Remus isn't the spy. Remus isn't the spy.

"I can talk to Remus and Mary," Em is saying, and Sirius snaps back to reality, "and you can tell Alice, if you want. I know you and Remus—that you probably don't—"

"No," Sirius interrupts, and Emmeline frowns. "I'll tell Remus. You tell Alice and Mary. I have some—I should hash out—I thought it was Remus, Em."

"You what?"

"The spy. I thought it was Remus, not Peter. I need to—to apologize."

She looks startled, but she nods. "Okay. I'm going to Apparate to Lily and James's house, then, so that I can tell them. I should—do you want Peter's old key to the flat, for later tonight? I mean, if you're going to be staying here…"

It's probably costing her something to give that up—to admit to herself that Peter isn't coming back—and Sirius suddenly feels a rush of remorse. "Hey. I'm really sorry about Peter."

"I am, too. Me, too."

xx

Remus is at home when Sirius Apparates to his building. Of course he is—three years later, he still hasn't been able to track down a job, thanks to having had to publicly register as a werewolf. Sirius knows this mostly from what James and Peter have told him, not because he'd been checking in on Remus. He hasn't really checked in with Remus in a long, long time.

"You thought it was me?" Remus asks haltingly when the whole ugly truth comes out—that Peter was the spy, that Sirius almost made him Secret-Keeper, and that Sirius had thought it was Remus all along. "This whole time, I thought you were avoiding me because you didn't care about me anymore—because too much had happened between us—and you're telling me that this whole time, you thought the spy was me?"

"You were poisoned—I thought they were blackmailing you—I thought you were acting shifty because you had something to hide—"

"I was 'acting shifty' because you didn't love me anymore!" shouts Remus. Sirius actually, literally stumbles backward—Remus never shouts. "I was 'acting shifty' because I couldn't stand to be around you and see the hate in your eyes. I missed you, and you thought I was the spy?"

"Moony…"

He has a sudden, overpowering urge to run forward and seize Remus and never let him go ever again, but he can't do that, of course. It sure as hell doesn't look like Remus can forgive him anytime soon for his mistake, and it's not like Sirius can have reunion sex at a time like this when he's just found out that one of his best friends turned traitor for Voldemort years ago. "I want to fix this," he says finally, with Remus staring at Sirius like he's never seen him before. "I do. But this isn't the time. The Potters haven't been able to leave their house in almost two years—Voldemort almost got them this week—Peter is in the wind—so many of us have died this year—Marlene is dead—"

"Right," says Remus. "Not the time."

They stand there staring at each other for a long moment, and Sirius can't decipher the look in Remus's eyes. "I should go," Sirius says finally. "I need to tell Dumbledore what's happened. I should have gone to him first, but I… I needed to see you."

"Right," Remus says again.

The look on his face makes Sirius, for the first time in an exceptionally long time, feel worried about Remus. He's all alone in this flat every day—his roommate, Benjy, dead at Death Eaters' hands—with no job to distract him from the war and no boyfriend to keep him company, not anymore. "Can I come back?" Sirius asks, his voice cracking. "After I talk to Dumbledore, can I come back? Can we just—sit for a while?"

But Remus turns on him. "I don't think that's such a good idea."

"Oh. Yeah. Okay."

Sirius has fished out Remus's Floo powder and is halfway into the fireplace by the time Remus speaks again. "I do still love you," he admits in a shaky voice. "I just…"

"Yeah," says Sirius. "I still love you, too."

And he straightens up on the hearth and tosses the powder to his feet. It's not until he comes out the other side into Dumbledore's office at Hogwarts that he realizes he never told Remus that he was sorry.

Dumbledore looks startled to see him, but his jaw sets and his eyes steel when Sirius tells him about Peter. "And this just took place this morning?" he asks, folding his hands together behind his desk.

"Maybe half an hour ago?" Sirius estimates. It feels like both shorter and much, much longer than that at the same time.

"Thank you for coming straight here," Dumbledore says. "I'll call an Order of the Phoenix meeting for tomorrow. And Mister Black?"

"Yeah," says Sirius tonelessly.

"In the future, you'll want to share your intentions as major as this with others before trying to enact them. Had no one else known that Mister Pettigrew was taking on the role of Secret-Keeper, the switch could have ended in disaster, not just for Mister and Missus Potter, but for you."

"Yeah," Sirius repeats, but after a second, he adds, "Actually, no."

"No?"

"No. When have you ever shared your plans with anyone? Because you're making us all think that you don't really have a clue what Voldemort's after or how to stop him."

"…Pardon me?" The twinkle is gone from Dumbledore's eyes, but he doesn't look angry, at least.

"Look," Sirius says, "someone has to say it. Marlene would have said it, and if she's not here anymore to do it, then I have to do it for her. I at least owe her that. The Death Eaters are picking us off like twigs, and what have we accomplished? We've turned in dozens of people who turned out to be under the Imperius Curse, and we've run some damage control on Muggle torture and killings. What's the grand plan here? How do we stop him? Because going to war with low-level operatives isn't getting us anywhere."

Dumbledore looks like he's about to speak but thinks better of it. Sirius is breathing hard. He hadn't realized just how much pent-up frustration he had in him, but now that it's out, it's out, and there's no stuffing it back in. Finally, Dumbledore says, "You ought to be proud. It's not often that anyone calls an old man who thinks himself wise on his failings."

Sirius just demands, "Do you?"

"Do I…?"

"Have a grand plan?"

Dumbledore breaks eye contact, studying his hands for a long moment. "The only true way to take down the Death Eaters is to take down Lord Voldemort. I have my suspicions," he tells Sirius, "of how Voldemort is protecting himself and how we can target those protections, but it would be foolish to risk lives on a hunch."

"We're already risking our lives every night just to keep others afloat," says Sirius. "We may as well keep risking them on a chance that we can cut the head off the snake."

Dumbledore just looks at Sirius for a long, long time. He's sure that Dumbledore's going to call him out in that disappointed way that manipulates you into feeling guilty, and he's totally caught off guard when Dumbledore says instead, "Mister Black, how would you like a new job?"