Title: I Know What You Do

Pairing: Zuko/ Sokka.

Summary: Post-series. Azula has always known about Zuko.

Disclaimer: I own no rights to the characters, plots or fictional universe that may be referenced herein. I make no money from posting this and mean no offence by it.


"I know why you joined them," she tells him, "For that watertribe peasant." She spits the word in his face with an extra serve of judgement and Zuko has to still his fingers from actively wiping his untouched skin off in distaste.

"Oh, not the girl," she continues, her smile widening to show her teeth, "that boy of yours."

He takes care not to react; merely stays where he is, off-balance as always where his sister is concerned. But he can't help the flush that starts, particularly when she's leering at him from the bars of a prison. He can't help the colour rising to his cheeks no matter how much he regulates his breathing. He can feel his heartrate pick up and he knows she can see his confusion.

"Poor Mai," Azula croons, "I tried to tell her. She wouldn't listen to me. How are you going to tell her, Zuko?"

"There is nothing to tell her," Zuko says. He says it with finality but when has that ever worked with Azula.

"What's his name?"

"It doesn't matter. There's nothing there. Let it be, Azula."

She shows her teeth like a shark and he has a split second to register that there's something more than innuendo in the air before she leans down- "Was it a secret? Father knew. He just didn't want to say. He made me promise never to say. But he's dead now."

"He's not dead."

"If you haven't killed him, you're an idiot. Look at you, my idiot brother who thinks he's being good but he's just crippled his nation and sold his honour."

"I have my honour." He can't help the somewhat grim smile. "I did get to the Avatar in the end."

"It doesn't count." She's pressed up against the bars so fast that he can't help his startled step backwards. "You cheated."

"But I still know," she continues, "All your vices. All your little sins. Is that why you won't kill me too? I know what you do."

She's almost singing those last words and yes, she does know. He's paranoid too and he sees what he fears most in her eyes.

"I know about the first one," she says, and she turns so that the back of her head is pressed against the bars, hair trailing thick and long against the metal, "He didn't really care for you. He just liked to think that he'd had the Prince. He wanted your title. Was that time in the sea your first time?"

"Stop it, Azula. That's not why I'm here. You said you wanted to see me," he says.

"I took him. Did I ever tell you that? The second one I didn't get. He loved you. He would wait, he said. I said he could scream your name all he wanted but he looked so horrified." She giggles. "I sent him to the front lines on a battle ship. He didn't get to wait for you. Would you have wanted him back anyway? I thought not."

Zuko swallows before he can stop himself, the breath rasping in his throat.

"He had brown hair," she whispers, "He was taller than you. He had blue eyes."

"Hazel," Zuko says and then frowns in self-hatred as she lets out peals of laughter.

When she's done she turns back to him, looking him firmly in the eye.

There are days when he doesn't know if she's still crazy or just differently sane. There are days when she seems so logical, so conscious of the world around her. Today is one of those days. He's learning to fear them as much as he hopes that maybe she can still be...

"You used to meet him by the pond in Mummy's garden," she coos, "And you used to let him do things to you. I saw you most times. You have a pretty cock, dear brother."

He flushes and glances quickly back at the door that separates them from the guards outside.

"And he would be so gentle, so loving. You were greedy. You would make those noises, always wanting more, like a cowpig at a feeding trough. Oink moo'oink."

She laughs at his gathering anger and he knows that she knows that she could still take him in a battle of skill, and in a battle of wills. It's only when it comes to a battle of good and evil that her house of cards falls over. Azula is always and eternally bad, because Azula wants to be.

In between self-preservation and envy, Zuko mourns what she could have been while he loathes her actuality.

"Is your watertribe peasant the same? I saw you once. I came to the temple and I saw you ride him. He was holding you by the waist like a girl. Like a whore!" This time she does spit in his face.

It's so unexpected and so sudden that he has no barriers up. He turns his head and wipes immediately at his mouth, his cheeks, his eyes, his scar before he can stop himself.

When he turns his head back around, she's already changed her tones. Her voice is gentle now, and she's pressing her pretty face against the bars of the cage.

"It's okay, Zuzu. I still love you," she croons, "It's okay. I know. Daddy was so big and so strong. All you wanted was his love and he couldn't love you. But they could. You didn't care what they did so long as they loved you. I know. I understand."

The image she's suddenly conjured into his head, of looking up at his father as he kneels before him in submission, is so intensely disturbing that Zuko actually feels his stomach twist. He takes one more step back. And he feels the anger drain upwards from the souls of his feet inexorably to the rough ends of his fingers.

"Are you going to kill me to keep me quiet, Zuko?"

Azula smiles at him through the bars, pretty and dangerous and chillingly logical.

He tamps down firmly on his anger and shakes his head. "You're mad," he says.

"Am I? Because I tell you the truth?"

"Everything you say is a lie."

"Well," she says, "You know how true it is. When you let him screw you next time, think of me a little and remember that I know. I've seen you. I can imagine everything you let him do to you just for a little love."

Zuko curls his lip in scorn but as he bangs past the outer door to leave, she says, "Give my regards to Mai," and his heart freezes.

He leaves her behind, and he tells himself for the umpteenth time that she's crazy, she doesn't mean half of it, she can't know anything, and if she can, then no one will believe her because she's crazy and they know she doesn't mean half of it, can't know much about it, and even if she can, then how can anyone believe her when she's so crazy...

He gets a headache as the half-articulated thoughts go round his head. He barely makes it through the day. He suspects the advisers know. There's so much to do but someone must have sifted through his murky past by now. He hasn't heard anything he recognizes but he is his father's son and he is paranoid. He fears they know too much. He stares at them for any signs and he shows his anger in a feeble attempt at normality but he feels weak and small and drained.

When it's night, he summons Mai, and he kisses her lips and feels some of her passion slip past her bored exterior. He stops when he knows he cannot reciprocate- not tonight, he tells himself, it's not seemly- and he sends her away with precise politeness.

She looks at him like she knows. She must know, he frets, because he's never hard when he kisses her. He wants to be, he wants to feel need for her, and passion. But he doesn't. He can't contemplate taking her roughly against the ground beneath an open sky, or even gently in a bed.

He struggles all night and he fails.

He rises with the sun and he makes his way to the room that he shouldn't know the way to. He doesn't bother to knock. He enters. And he finds a lump of dark skin and knotted mouse-brown hair curled beneath a light sheet and snoring peacefully.

And helplessly he feels the tendrils curl in his belly. He feels the heat rise from his heart and his head and go all the way down until he's clenching his gut in an effort to stave off the wrenching need that almost always ends with him wrapped around this absurdly irreverent boy, pleading brokenly for more in any way that Sokka will consent to give it to him.

Zuko wants to run. He wants to run to Azula and make her swear never to tell, kill her so she can't tell. He wants to go to his father and demand that he speak about it, but he doesn't know if Ozai- Father, Father- ever knew at all and even if he did, Zuko knows Ozai's views on the matter. He knows what Ozai would say, the cruel twist of the lips that signals distaste and disapproval, magnified by a sardonic delight in hurting his failure of a son and heir.

Zuko drops to his knees beside the bed and he runs a shaking hand over the curve of Sokka's skull before he suddenly gathers a fistful of hair and pulls. He doesn't know why. But he wants to hurt Sokka, wants to see if there will be disapproval. Small disapproval perhaps, but he'll take any at the moment, just to show that he isn't being paranoid.

The first one didn't even care, Azula said. Zuko cared. The first one had been older, infinitely beautiful, infinitely hurtful. Rough and needlessly tortuous. Enjoyed his title more than his body, Azula said. Zuko knows that Azula always lies but if there is any hint that Sokka feels the same way then he thinks he may break his heart again.

He can't take the waiting while Sokka blinks owlishly at him. He doesn't trust the way Sokka smiles. He certainly gets suspicious when he catches an odd look in those blue eyes.

Cold, he thinks, calculating.

He gets up hurriedly and leaves before Sokka can say a word more than 'Zuko'.

He goes to the garden and he sits there, with his head in his hands. Sokka comes to find him there an hour later, looking so sympathetic.

Sokka's a good actor, Zuko thinks bitterly.

"I told you not to see her yesterday."

"Don't touch me."

"Zuko, you're crazy."

Zuko looks up and up and he feels that he might as well be on his knees for this as Sokka is standing over him and Zuko is so low to the ground. He thinks of his father looking down on the tears on his face that evaporated at the first blast of fire, the searing pain, the smell of burning flesh. He thinks of Azula as he slides his hand into Sokka's trousers, confusing his lover all the more as his desperation makes his hands shake.

She knows, he thinks, and he can't forget how wrong this is and he also remembers Mai. It's with a sickening feeling that he remembers Mai as Sokka lets go and Zuko has to swallow or spit the semen out into the grass his mother sat on.

He swallows, because it's easier to keep it all inside.