Narcissa had been the first one that Bellatrix had told about the affair.

She could still, all these years later, remember every detail of what had happened.

Narcissa was sitting in her parlour, an embroidery hoop in her lap, gently stabbing herself with the tip of the needle instead of sewing and watching little beads of blood bubble to the surface of her skin and burst when she touched them. It was hypnotic, watching the tiny crimson blossoms appear on her fair hands.

There was a knock on the door and Narcissa rose swiftly, brushing the blood from her fingers on her handkerchief, and when she opened the door, she was met with Bellatrix, whose eyes were glazed over and who had a positively beatific smile on her face.

"Bellatrix? What's happened – is something wrong?"

"Nothing's wrong, Cissy..." Bellatrix breathed. She pushed back her hair, which was loose and tumbled around her shoulders in dishevelled ringlets. "Nothing's wrong – everything's completely right... may I come in?"

"Of course…" Narcissa beckoned her inside, her heart beating quickly. She was unsure whether she liked Bellatrix in this state. It was unnerving to see her strong, eternally composed older sister flushed and near to giggling like a schoolgirl. It, in fact, made Narcissa rather nervous.

Bellatrix floated in, her lips curved up into the widest smile that Narcissa had seen her wear since her wedding day, when she had strode down the aisle with such confidence and been taken into Rodolphus's arms…

Don't think about that, Narcissa, don't you dare start thinking about that!

"What is it, Bella?" Narcissa asked.

In answer, Bellatrix pulled up the arm of her dress, and Narcissa flinched. She had known for a long time that her sister had intentions of joining the ranks of the Death Eaters, along with Lucius, along with Rodolphus and Rabastan and so many men that Narcissa could not have named if she had tried, but she had never fully expected Bellatrix's dream to come true. She had, in fact, been praying that it would not, for as soon as Bellatrix was a Death Eater, that meant that Narcissa was the only useless sister left…

"You… you were marked," she said flatly, staring at it.

"I was," Bellatrix breathed, and she actually twirled in place. "Oh, Cissy, I can't even say what it was like…" She pressed a hand against her forehead and sank down very slowly into the armchair in which Narcissa had been sitting before she had come to the door.

And I don't care to know what it was like, thank you very kindly.

Narcissa loathed all manner of talk about the Death Eaters. It sickened her, for she knew – she knew, very deep down, in ways that she couldn't entirely explain and that she was quite aware were not the most clever or logical, but she knew nonetheless – that the Death Eaters would be the downfall of her sister.

She was sure of this, no matter how many times Bellatrix insisted that she was safe.

"The Dark Lord is an incredible man," Bellatrix breathed, brushing hair back from her forehead and smiling again at Narcissa with that frighteningly beatific smile. It did not suit her.

"Is he?" Narcissa ground her teeth together lightly. She wished that Lucius would come home quickly and free her of the burden of having to listen to her sister wax poetic about the many ways in which the Dark Lord surpassed all other men – he was better spoken, more handsome, more accomplished, and any number of other things that Narcissa suspected that Bellatrix would not have cared about, had they not been connected to the Dark Lord, but that, by the very virtue of being connected with him, were the only matters of which Bellatrix would speak.

"He is," she confirmed, then she looked at Narcissa and the airy, sweet and angelic expression that she had been wearing slipped from her face. "Narcissa… I must confess."

That made Narcissa alert instantly. She stepped close to her sister and could feel her heart beating a quick and dizzying pattern against her bodice. "Bellatrix? Confess what? Confess what, Bella – is it a matter concerning the Dark Lord?"

"Yes," she breathed.

She is in danger. I am in danger. She has put herself in danger. She has put me in danger.

"What?" Narcissa asked in a small, tremulous voice.

Bellatrix looked fair ready to burst with joy. She leapt to her feet and caught Narcissa in her arms. "Oh Cissy, you- you will be so happy for me!"

"I will? And why?"

Bellatrix pulled back, and her eyes shone so brightly that Narcissa thought her feverish. She laid a hand on her cheek, an action which it seemed Bellatrix mistook for affection, for she put her hand over Narcissa's, then moved it to her lips and kissed her fingers.

"He took me to his bed," she whispered ecstatically.

Narcissa blinked. She had expected some declaration that Bellatrix would soon be running off to participate in some deadly mission halfway across the globe, or perhaps to be told that the Dark Lord had some use for her and that she was to come to his manor immediately to serve his every whim.

Clearly, Bellatrix did a fair enough job of serving his every whim.

"Well," Narcissa said, pressing her lips together disapprovingly, "I don't see what that has to do with me–"

"I wanted to tell you! You are my sister!" Bellatrix looked rather insulted. She pulled back and crossed her arms defensively across her breast, blowing a loose thread of hair out of her eyes with an impatient huff of breath. "I would have thought that it would be of some interest to you that your sister had just bedded–"

"I do not care to hear the sordid details of your sex life, Bellatrix," Narcissa said. She tried to sound imperious, but her voice broke down at the end of the line. She struggled for a moment, and then, as Bellatrix continued to glare at her, she could not help but burst into a small fit of giggles. "Oh, stop that! It's rude to stare!"

"It's ruder to giggle," Bellatrix said, but a smile was inching onto her face too. "I can tell you about it, can't I, Cissy? You don't really mind, do you?"

"Of course not." Narcissa's laugh died away, but she kept her smile hitched onto her face and sank down into an armchair opposite Bellatrix and folded her hands in her lap quite politely, then looked at her older sister with an expectant smile. "Tell me, then."

Bellatrix clasped her hands at her breast and tipped her head back, staring up at the ceiling. "It's… oh Merlin, Narcissa, it was so incredible… after the ceremony where he marked me, he took me up to his bedchamber…"

"I would have guessed that, wouldn't I?" Narcissa said dryly. She was digging her fingernails lightly into the palm of her hand to distract herself from how she wanted to slap Bellatrix. "You did say that you bedded him…"

"I don't think you really want to hear this at all, do you?" Bellatrix asked, frowning. "You aren't happy for me at all, are you? I mean, I would have thought that you would be at least a little interested in your oldest sister being taken to bed by the Dark Lord…"

"Aren't you supposed to be married?" Narcissa snapped, losing all patience. "Doesn't that bother you in the slightest? You have a husband who you ought to be a little ashamed of being unfaithful to…"

For the first time, Bellatrix's angelic smile faded. She glared down at her sister. "Oh, thank you so much, Narcissa. You just had to drag him into this, didn't you? God, Narcissa, you're such a brat - don't you think that I can make my own choices about the men I sleep with?"

"Obviously not," Narcissa said quite snappishly, "because you've chosen the Dark Lord instead of the man you married. There are plenty of women who would have killed to be with Rodolphus, and you just cast him aside…"

"He's dull," Bellatrix said, waving one hand through the air as if waving Rodolphus and his dullness away. "He isn't anything like the Dark Lord. Oh Cissy, the things he did to me…"

"Lovely, kinky things I'm sure." Narcissa stood up and crossed the room, wrenching the doors of a cabinet open and pulling out a bottle of wine. Her hands were shaking and she needed the drink to steady her nerves. "I'm sure he was absolutely wonderful with you and knew every single thing you wanted…"

"Yes, he did." Bellatrix stood up, and though Narcissa kept her back turned to her, she knew that she was advancing threateningly on her. "Yes, he knew exactly every last thing that I ever could have wanted, all the things that I never would have dared tell Rodolphus about - what, does that bother you, Cissy? Because Lucius doesn't know?"

"No," Narcissa said immediately.

"So you don't deny that Lucius doesn't know?"

"I would never have denied it," she said quietly, still with her back turned to Bellatrix.

She would never have told anyone that Lucius knew what she desired, never would have said that he was some sort of prodigy in bed and understood her to the very depths of her soul, but she would certainly have said that someone else did.

It was so unfair. It was so unfair that Narcissa was married to Lucius when she loved another man and he loved Bellatrix… it was a farce, a mockery of real life, and it sickened her.

Rodolphus would not leave Bellatrix before - Narcissa had begged him time and again to divorce his wife and run away with her - but now she was going to bed with the Dark Lord, and he was still married to her, and Narcissa doubted that he would ever leave her, no matter now much Narcissa wanted him to, no matter how little Bellatrix deserved him, even though she was unfaithful to him, even though she very clearly preferred the Dark Lord…

"Jealous," Bellatrix breathed, her lip curling. "You're so petty, Cissy. You don't want me to be happy at all, just because you couldn't find a man who pleased you…"

"And what makes you think I couldn't?" Narcissa snapped. She whirled around to stare down Bellatrix, and her whole body was heaving with suppressed rage. Bellatrix regarded her with mild curiosity and surprise.

"Did you, Cissy?" she purred. "Do tell… have you found a man better than your husband?"

Narcissa would have paid dearly - more than paid dearly, she would have gladly given Bellatrix everything she had - to be able to tell her, to be able to watch the look on her face when it dawned on her that her sweet, innocent little sister was having an affair with her husband.What would she do, Narcissa idly wondered. Would she fly into a rage, or would she laugh and tell Narcissa that she had suspected it for years because neither of them could even begin to keep a secret?

But Narcissa couldn't tell her. She couldn't tell her because she was afraid of what she would say - what if she was furious and told Narcissa that she never wanted to see her again? What if she told Lucius that his wife was a harlot…

What if she left Rodolphus?

Narcissa couldn't do that to Rodolphus. She could pray that he left Bellatrix, but she knew that he never would, because he loved her - no, not even loved her. Love was a pure and sacrificial thing like Narcissa felt for him. What Rodolphus felt for Bellatrix was more obsession than anything else, an obsession with having the most beautiful women that any of them had ever known as his very own. If it had only been love, he would have left Bellatrix the moment he realized that she desired another, the way that Narcissa was willing to watch Rodolphus with Bellatrix and not say a word. It was more important to her to see her beloved happy than to see him with her.

So she said nothing.

"I am happy for you," she managed to tell Bellatrix, after a very long time of struggling with herself to be sure that the words "I am bedding your husband" didn't slip from her mouth.

"Are you?"

"Dreadfully happy," Narcissa said, and she hitched a sweet mask of a smile firmly onto her face. "I couldn't be happier."

And Bellatrix had believed her.