She was crying silently, slowly, over a cup of tea when Sirius got up in the morning. He almost didn't say anything, thinking that perhaps if he was silent she would wipe her tears and smile again and everything could go back to how it was. But then she looked up at him and he sighed, and the moment was gone.

"Something."

It was all he had to say. She nodded, and looked down at her tea.

"I don't know what it means," she said as he sat at her feet, pulling them into his lap, rubbing the arches gently, with just enough pressure not to tickle her. "But I've been seeing something, and I don't like it. I don't know why, but I know it's something that's going to ruin everything."

"Tell me, love," he said, kissing her knee. "Tell me and I'll do everything to fix whatever's wrong."

She frowned, rubbing the heel of her hand into her forehead. She closed her eyes, perhaps trying to get a clearer picture of whatever she was seeing.

"There's a fireplace," she said softly. "The stone is black, and it's…it's surrounded by a dark wood. And…. Sirius, it's the strangest thing, I think there were animals on the ends of the mantle."

"What animals?"

"Snakes," she whispered, frowning. "They were shining black snakes, with fangs out."

Sirius felt the blood drain from his face, because he knew that fireplace, and he knew it well. Except it wasn't at Lestrange Manor, it was at Selwyn Manor, and whatever was going on here was well beyond his ability to understand.

"Cat, we have to see Dumbledore, and we have to tell him everything," he said softly. "We have to see him now."

"I'm afraid."

"I'm going to be with you," he said earnestly, pressing his hand to her knee, looking up at her wide brown eyes. "I'm going to be with you every moment."

While she finished her tea, he sent a message to Dumbledore that they needed to meet urgently, that Catherine had begun to remember important things, and a message arrived almost immediately that they were to come to Hogwarts with all haste.

They dressed, and Sirius Disapparated them to Hogsmeade, and he walked her up to the gates, where Hagrid met them solemnly. They walked silently up to the castle, up to Dumbledore's office, and Sirius could feel the hair on the back of his neck standing up as he recalled the last time he was standing in front of the wooden door into Dumbledore's office, getting in trouble for some final prank. He hadn't been afraid then, but now he couldn't stop thinking the worst.

"Enter," the tired voice of Dumbledore said as soon as Sirius began to knock, and Sirius gave Catherine one last glance before opening the door.

/-/

Albus nodded as they finished their story, and he looked at Catherine with a variety of possible plans for figuring out her secrets, ones she obviously didn't know she had. Of course, there would be no easy way for it.

"The mind is a complex thing," he said, pressing his hands on the table, and looking specifically at her. "It takes incredibly powerful magic to seal the mind, and even more powerful to do it with such careful specifications. To unseal it, to release your memories, it will be painful, potentially traumatic, and exceptionally difficult. But I feel that we may longer have no choices. Forgive me, my dear."

She was trembling, and Sirius looked afraid for the first time in all the years Albus had known him. He hated having to ask Sirius to wait outside the room. It would only be harder for him if he could see her as Albus released the holds on her mind. The sight would be strain on Sirius that could jeopardize everything.

"I have to ask you to wait outside," he said softly. "It is better to limit distractions. Please, Sirius, it will not be long."

The young man hesitated, but he did ask asked, pausing only to whisper a word of encouragement in Catherine's ear. When the door closed, Albus turned back to Catherine, smiled sadly, and said, "Well, my dear. Let us begin."

/-/

Sirius paced back and forth several times, once even punching the stone wall nearby. What felt like hours later, although it was probably closer to minutes, Dumbledore opened the door again, with a weary look in his usually sparkling blue eyes, and he said, "I will be back shortly. There are some things I must see to. She needs company. Do not press her. She will tell you what she can, and I will return to speak with you shortly."

Nodding numbly, Sirius went back into the office to see Catherine on the floor, trembling. She was hugging her knees to her chest, but she wasn't crying. Just on the off, Sirius would have said she was in shock. He sat down at her feet, placing a hand on her hands where they were locked together. He felt he should say something, but there was nothing to say for the first time he could ever remember.

After several minutes of silence, of her not looking at him but just shaking, she finally said, "Everything I thought I knew was planted. And I…. Sirius, I was so unhappy."

He squeezed her hands and waited. It took several more minutes for her to close her eyes and sigh shakily.

"There's one party," she said softly. "God, I must have been five, maybe six. And I had this beautiful dress. I felt so pretty, so proud. And I…I ran into this man when I was trying to get to the food, and he spilled his wine and he was so angry. His face was just so…angry. And I hurt everywhere. It all happened so quickly, and I think I was screaming or crying or something, but then it suddenly stopped." She paused to wipe a bit of hair out of her face with a shaking hand. "And there was this boy, a little older than me, and he said it was his fault, that he'd run into me and knocked me over. And they didn't do anything to him, but the man left me alone and the boy just walked off. But he hadn't touched me, it was a lie." She shivered. "Like he knew exactly what would happen if he lied for me."

Sirius felt suddenly cold, and he tried to find something to say.

"I never went to any more parties after that," she said, rubbing her temples. "I don't think I ever saw the boy again."

Dumbledore was back with Madam Pomfrey, who did not seem to know exactly what had happened, but she ushered Catherine out of the room with a gentle expression and the promise of something to help her with the shock. Sirius pulled himself off the floor, wondering if he should go with her, but then he remembered that Dumbledore had promised to explain things to him, so he sat down, his head swimming.

"She said it was all not real," Sirius managed to say, but his voice didn't sound like his voice.

"Yes," Dumbledore said softly, pressing the tips of his fingers together. "Yes, unfortunately for the poor girl, someone did a very careful job on her memory. They took away every real memory she had and planted two very specific false ones, one of a bedroom, the other of a name that isn't her name."

Sirius's head jerked up at this.

"Yes, the poor thing. The one thing she was sure of, and it was a lie." Dumbledore sighed. "Her real name is Cara."

At this, Sirius stood abruptly, something tickling the back of his own memory. A young girl he'd met a few times, someone spoken about only in scandalized whispers. Bastard children were an expectation, usually with some whore, or a half-blood secretary or something of the sort, but bastard children between two married purebloods were a ghastly thing, his mother had always said. And as far as Sirius knew, the only one in recent memory was Cara Selwyn, daughter of the wife of the Selwyn patriarch (a Rosier by birth) and the Lestrange patriarch, Rabastan and Rodolphus's father.

"She was raised in shadows," Dumbledore was saying as Sirius was pondering Cara's story. "Very little magical ability, so when she was of age to start showing signs of magic, they hid her away in fear that she would be a Squib and not eligible to make even a marriage on the lower end of the chain of the great families. She did show signs, but late, and received very little training."

A little girl, screaming as her own biological father tortured her for staining his dress robes. Sirius had been so angry at the man; he'd taken responsibility for the stains himself. No one would dare touch him, not in public, not like this. The heir of the house of Black. The girl was spared, and Sirius walked away to find his brother to tell him about how stupid Lestrange looked when Sirius stopped his bullying. A grown man, outdone by a seven-year-old boy.

The room felt so cold.

"The idea was something like what Alastor has been suggesting, although not as a spy, but as bait."

Sirius looked up at Dumbledore, horrified.

"It seems to have been your cousin's idea," Dumbledore said softly as Sirius sat down again, collapsing into the chair. "You see, they expected very much that your Gryffindor chivalry would compel you to care for her, to protect her, and so when the time came, when her memories began to be released and we did what had to be done, you would do what you must to keep her safe."

"What do you mean?"

"They will take her back, Sirius," Dumbledore said, his eyes terribly sad. "It is a matter of time, and they will begin to look for her, lay claim, and we cannot keep her."

"But she's of age," Sirius said, outraged. "She can stay! She can run away! I did."

"Your mother did not look for you," Dumbledore said. "The whole plan hinges on old laws, and they have every right to take her back. But you know what will happen if she goes back and you do not follow her."

Sirius nodded, recalling with disturbing ease the news article about Peter's death. A spy discovered doesn't have any use anymore, and they hadn't had any use for Cara Selwyn for years.

"Why me?"

"You are powerful, Sirius. You are talented, and exceptionally pureblooded. You are, in many ways, the symbol of what so many of the Death Eaters are fighting for, and the fact that you of all people have become a blood traitor is a very heavy blow. Not to mention, if they have a hold strong enough on you, they would get much more out of you as a spy than they did out of poor Mr. Pettigrew."

Sirius felt sick to his stomach. If he didn't do this, if he didn't join the Death Eaters, Cara would die. He knew his cousin, knew that whole world, too well to doubt it. But to join the Death Eaters, to do the sorts of things they did for their despicable reasons…. How could he look himself in the mirror ever again?

"I don't think I can."

"You can," Dumbledore said with surprising firmness, "and you will. Because if that girl dies, you will never forgive yourself, and I daresay you are clever enough to lead a double life." Sirius's head jerked up again, astonished at what was being suggested. "Lord Voldemort is not the only one who sees the value of double agents, Sirius."

The room was definitely cold. They should really work harder to do something about that. Sirius stood up, but he was dizzy. The room was spinning.

"I…I need…."

"Talk to the Potters and Remus," Dumbledore said, seeming to read Sirius's mind. "And remember that you may not have much time at all."

Sirius nodded, wanting to go to Catherine – Cara. But she might not even be conscious, and Dumbledore was right. There might be no time. He would see Lily and James.

"Oh, Sirius," Dumbledore said when he'd put his hand on the doorknob. Sirius froze. "I thought you should know that many times when children are young, their eyes, like hair, is lighter than it will be, and then they darken with age. A very common thing, actually. So a person with brown eyes might, as a child, have had eyes that were, perhaps, gray?"

With almost terrifying ease, Sirius could see the five-year-old Cara Selwyn standing before him, with beautiful dark hair, the palest skin, and such brilliant gray eyes. More than a decade later, and here he was again, faced with a choice that could save her, only this time he was no longer a child, and there would be massive consequences whatever he chose.

Childhood over, indeed.

/-/

James nearly dropped the plate he was drying at the sight of Sirius's face looking, well, heartbroken. It was the only suitable word James could think of, and it was an expression he never expected to see on his best friend's face.

"Oh, Sirius, what's happened?" Lily asked, trying to take his coat, only to be shrugged off by a distraught Sirius. "Sirius, what is it?"

"Remus," he said softly. "Get Remus here. I need to tell you all at once."

Lily hurried to call Remus, and James put the kettle on, before digging out a bottle of firewhiskey. Sirius sat at the kitchen table of their cottage with a look on his face like was going to be sick.

"Mate, have some tea, yeah?"

Sirius shrugged. James exchanged a worried glance with Lily when she came back with a puzzled Remus, who must have come through with Floo.

"Four cups then," James muttered to himself, nodding at Remus before getting the tea ready. By the time he passed around the cups, he realized Sirius's hands were shaking.

Very slowly, in a voice strangely strained, Sirius told them of how he'd taken Catherine – who apparently wasn't named Catherine at all – to Dumbledore, and how her memories were unlocked, and how she was actually a tool the Death Eaters were using.

"I don't understand," Lily said, stunned. "What did they hope to gain from it? We haven't let her into meetings. She doesn't know anything."

"It's not about what she knows," Sirius said, slamming the cup down, his face contorting with anger. "It's about me!"

"You?"

"About my bloody chivalry! Do you see, Lily? If I don't go with her when they take her, if I don't make certain she's okay by selling my bloody soul, they'll kill her and they won't even shed a tear, except maybe her stupid cow of a mother." Sirius stood up pacing the kitchen floor rapidly. "And Dumbledore thinks that he can just ask me to spy, like that makes it all better."

James held his breath and looked around at Remus and Lily. Remus was covering his mouth, although it wasn't open, with a shaking hand, and his eyes were on his barely-touched cup of spiked tea. Lily's beautiful green eyes were so wide, it almost looked painful.

If he was being perfectly honest with himself, James had long suspected that someone from Sirius's family would pull some elaborate scheme to pull him back into the fold, although it seemed to be running late, and of a different character than he'd anticipated. But then, Bellatrix had always been a touch sick in the head.

"If you don't do it," Remus said softly, "they'll kill her."

"Yeah," Sirius sniffed, his back to them as he leaned over the sink. He was pressing into the edge of the sink so hard with the palms of his hands that James thought he might even hurt himself.

"And if you go, she'll be okay?"

"I imagine," Sirius said bitterly, "that the deeper into it I get, the more I can guarantee that, but yes, if I sell myself she'll be more or less okay."

"And maybe," Lily said, as if she had an epiphany, "if you get in deep enough, then she'll be safe and we can end this war."

Sirius turned around and looked at her like she'd said something atrocious.

"You don't see it, do you?" he said, near tears. "Don't you understand what this means, Lily? One of those things on my arm, torturing Muggles, Muggleborns, maybe even killing innocent people! My talents, Lily, they're not cerebral. I might have to kill people, maybe a lot of people, just to keep her alive, do you see?"

"Except," James said, frowning at Sirius, "it's not just for Catherine. No, don't, Sirius. Whatever her name is, Catherine will always be her name for me. And you can tell her that's how we all feel, because it is. Sirius, if you do this, if you play this right, you can save more than just her life. You could end the war, save us all. Do you see?"

Sirius shivered, his eyes glued to James's. That they were brothers, in spirit, had never been just a game to James, nor to Sirius. In some ways, Sirius was as much James's soulmate as Lily was, and he knew just how much this choice was tearing Sirius apart. Before freeing himself of the bonds of his family, Sirius had never truly been happy, and when he ran away from home just a few years ago, it was like he'd been given a new lease on life, the lightness of childhood all over again. And now, looking at him, it was like all of that was gone again, and whatever it was Sirius had run away from, it had caught up to him.

"It's so cold in here," Sirius said, his voice something of a croak. "Merlin, is the whole world cold?"

"If you don't do this," James said softly, "they kill her, and they crush you, and they win. And if you do this, the game is still in play, do you see? Because they'll think they've won, but what they're really doing is giving you a new hand to play with. Bellatrix thinks she knows you. So prove her wrong."

Sirius nodded, and the three of them watching him knew that he gave in to what he had all along known he would have to do. Sirius slid to the floor, and Lily got up when Sirius began to sob, but James shook his head, putting a gentle hand on Lily's arm. Without a word, James stood up and led the other two out of the room.

As long as no one said a word, Sirius could pretend that none of them had seen, had heard. There were some things, as Lily had yet to understand, that a Marauder had to do in private.

A/N: So… :D Big reveal! Catherine is actually Cara Selwyn, and not exactly a spy but not exactly not. Some of you got surprisingly close to figuring it all out. I'm super impressed. And now Sirius has a terrible task ahead. What's to come? Sirius meets Voldemort. Want to see that meeting soon? Ten reviews gets an early update!

Review Prompt: Now that Sirius is essentially becoming a double agent, who are you most excited to see come into the story from the Death Eater camp? Personally, I'm excited to start showing y'all my version of Sirius's family members (Regulus, Narcissa, Walburga, Orion).

-C