Clary woke, gasping out of a dream of a city all of blood, with towers made of bone, blood raining down from a scarlet sky.

She sat bolt upright, clawing at her chest to wipe away the last remnants of her dream. Her palms were wet and clammy, her hair pasted to her neck with sweat. The light in the room was dim, the witchlight lamp on the bedside table the only illumination, giving off a whitish glow that cast a pool of light on the black marble floor; red fabric was strewn across it, like puddles of blood.

She was on a bed whose white sheets were twisted about her ankles in a tight spiral. The room itself was large, windowless, with wood panelled walls. There was no furniture in the room, save for the bed and its nightstand. Across from her was a door; light flooded through the gap beneath it, carrying warm steam into the room like smoke from a smoke machine.

Clary was dimly aware that her muscles ached; her back felt twisted, as if she had slept at a funny angle, and her lip felt strangely swollen. She frowned as she climbed out of bed –

And the bathroom door swung open.

Sebastian stood in the doorway in a cloud of bright light and steam, the light filtering around him like a golden flame. He'd clearly taken a shower; his silver-white hair was tousled and dripping water over his face and a plain white towel was slung about his waist, exposing his bare chest and the hard, compacted muscles beneath the skin. His eyes, Clary noticed, seemed to bulge out of his pale face, like black rocks of burning coal.

He ran a hand through his fair hair; it came away dripping. "Awake so early, little sis?" he said. "I would've assumed after last night you'd be snoring and drooling until noon."

Clary tried not to stare at his bare torso as he came toward her, his feet leaving wet footprints on the marble. It was difficult, she thought, to hate someone so striking. Steam rose off of him like smoke off a fire, and when he reached her, she could feel the heat of him radiating through her body. She hated it.

He reached up to tuck a stray curl behind her ear, his fingers shaping her jaw until they came to rest beneath her chin. He tilted her head back, his thumb running over her swollen lower lip. "Good. No real damage." His eyes searched her face. "The injuries were worth it though, right? Last night was…"

A small explosion went off in her head. She blinked. "What do you mean?"

The look on his face made her insides twist in on themselves. "You don't remember?" His grip tightened on her chin, nails digging in. "Clary, we…" He shook his head, releasing her chin. "Nothing a little Memory rune can't handle, I suppose." He rooted through the drawers on the nightstand before turning to her, stele in hand. Taking her by the arm, he scrawled a black Mark on her inner forearm, its touch burning.

As he drew, the room began shimmering around her, her vision blurring. Sebastian was now a faint glow in the dimness, silhouetted by the glow of the light streaming in from the bathroom. She felt his hand tighten around her arm as she stumbled into him, her face slamming into the wet skin of his chest. Her mind was whirling. Images darted in and out of view behind her eyelids.

She closed her eyes, listening to the steady beat of her brother's heart as the Memory rune took effect.

There was a crash, followed by laughter she recognised as her own.

And then, suddenly, she was slammed back into her body, the events of the night before dragging her under:

Clary stood in front of a wooden door. She could still smell the sweet, rich smell of faerie drugs. Somewhere in the back of her mind she saw the explosion of sparks rain down around her like angels falling from the sky, spattering her hair and body with silver droplets.

She stormed through the door and slammed it behind her. The room had been in darkness; when she walked in, it blazed up in brilliant white witchlight, momentarily blinding her.

Her body felt drained. Her scarlet dress stuck to her like a second skin with sweat. She jerked at the straps now, wanting nothing more than to have the stupid, sticky thing off of her and climb into bed. It seemed to meld to her body. She gritted her teeth, tugged –

A hand came down on hers. She froze. It was a callused hand; she could feel the rough edges of battle scars. Her heart jumped in her chest. Jace, she thought. But no, she realized with a jolt. Jace's touch was warm, comforting, and sent bolts of electric coursing through her veins. But this touch only burned her skin like acid, and even before she turned, she knew exactly who it was.

Sebastian. He was looking down at her with serious black eyes. His face was streaked with silver powder as well, the sticky stuff matted in his fair hair. His mouth twitched at the corner. "Need a hand?"

His hand came down on her shoulder again; slowly he began to move the strap down her arm. Clary swallowed. "I have two, thanks," she said, and she found her gaze wandering to his lips. She wondered if they felt as soft as they looked. "Sebastian–"

"Clary." He moved toward her until they were pressed against each other. He was so much taller than she was, probably as much taller as Jace was.

Her strap draped down her arm now, but his hand continued to move, and a moment later his palm was pressed against the small of her back. With his other hand he reached to touch her cheek. It sent prickles over her skin.

"Sebastian–" She tried to disentangle herself, but his grip on her chin only tightened. "Let me go, Sebastian."

"You know," he said, "in movies, all this hatred you feel for me would be categorized as sexual attraction."

"Stop. I don't – I don't want this– You're my brother–"

"You never cared that I was your brother before." His eyes were blazing. "Either way, you're exactly like me."

Clary shook her head rapidly. "No, I'm – I'm not. I'm nothing like you–"

His grin was diabolical. "Oh, but you are." His grip on her chin loosened; slowly he began to move it down, his fingers scraping her throat. "You just won't admit it. You killed our father, never given it a second thought. You faked friendship, faked caring – why else would you be here? You came here, to Pandemonium, to spy on me, to fake caring for your big brother, when all along your only duty is to gather information for your little Shadowhunter friends." He chuckled at her gasp of surprise. "Now," he breathed, and his hand ran over her breasts. "Tell me you're nothing like me. Look me in the eye, and tell me we're not meant for each other."

She looked at him, really looked at him. His eyes were all black, with a ring of silver circling the pupil. They were fathomless, empty, like dark tunnels. People often marvel at how alike you all are, said the voice in her head. He and your mother and yourself. His name is Jonathan; he has always protected you. He is your brother. He is your brother; he has always taken care of you. She looked down, at his hand pressed against her chest.

She heard him suck in a breath. "You can't. You can't do it. Clary," he said, and pressed her against him with his hand at her back. Heat radiated off of him like fumes off a fire. She could feel the beat of his heart through his shirt, like the flutter of a bird's wings. "Who do we belong to but to each other?"

Clary craned her head – and did a double take. His eyes were no longer empty pits of black coal, but green, green as spring grass. So much like her own. He has always had green eyes. For some reason she saw whip marks and black eyes, but she didn't know why. "We belong with each other," she said as she realized.

"That's right," he said, and his mouth came down on hers, hard.

For a moment she was back in Idris, standing amongst the ruins of the Fairchild Manor, and Sebastian was kissing her. She remembered feeling the wrongness of the kiss, as if a dark hole had opened up in the ground, threatening to suck her in. But this – this felt right. She was a Morgenstern, he was a Morgenstern, and they were the only family they had – who else did they belong to but to each other?

She leaned against him. His lips moved against hers, hungrily. He tasted of acid. She reached up, fisting her fingers through his hair, yanking at the knots of silver powder. The darkness consumed her, licking up her body like wildfire. Her heart beat faster.

He gasped against her mouth. Clearly he hadn't expected her to kiss him back, but she did, she kissed him back with as much force as if she were pushing against a solid wall. The hand that was pressed against her chest fisted in her dress, and he pulled her toward him, their bodies melding together as if they were made for each other and no one else. Her hands explored his body, running over the muscles of his biceps, his solid chest – she could feel the pounding of his heart beneath her hands – her fingers racking up under his shirt and raking her nails across the skin there.

"Clary." He was gasping her name against her mouth. And then the kiss deepened, become more aggressive and fierce and wanting. She could feel that he wanted her, feel it in the way his hands ran over her body, shaping the curve of her breasts, her arms, his tongue licking across her lips, making her want more of him.

She made a noise of surprise but didn't pull away when he lifted her up and slammed her against the wall. She heard the sound of the wood cracking from the blow. He was pressed against her now, and his hands gripped around her thighs, nails digging in. Her legs, hitched around his waist, were shaking with burning desire. He was moaning against her mouth, making her want more. She could smell the wicked, acidic scent of him, ticking her nostrils. Her fingers were laced through his hair; his, on the other hand, were all over her, pulling at the straps on her dress and snapping them.

He bit down on her lower lip, hard. She tasted blood, her own, mixed with his – she must have bitten his lip, though she couldn't remember. He was driving her crazy, groaning against her mouth and pressing her back harder against the wall. His hand found the hem of her dress; slowly he began to trail his hand up her leg, and a moment later her dress was racked up around her waist, and he was carrying her over toward the bed.

She crashed against the scattered pillows. Sebastian was on top of her, hovering inches above her like a dark angel. He looked down at her with blazing eyes as his fingers tickled down her right leg, and he drew it up, hitching it around his hip. She closed her eyes. She could barely stand it, being so close to him and yet so far away – she wanted him against her, to feel the pulse at his throat, the smell the dark scent of him so there was nothing separating them –

And then his lips were moving against hers again, and she found herself smiling against his lips. The scent of him was concealed with sweat now, and he was panting, breathless. His fingers dug into her hips with so much force the dress ripped – and then he was tearing it off her, lifting her up so she sat against him while he tore impatiently at the material and flung the shreds across the room.

The room seemed to shimmer around her then, as if she were looking through a wall of water –

"You are mine now," Sebastian breathed against her neck. His teeth grazed her skin there, biting hard. She gasped. "You belong to me–"

She heard a chuckle.

Her eyes flew open. She was still in the same room, lying on the same bed, shreds of dress littering the floor. A wave of nausea gripped her – could all of that have been real? Did she really sleep with Sebastian? Could she? No, she thought as glanced down, looking at the oversized shirt she wore. It barely covered her waist.

Another chuckle sounded through the room. Turning on her side, she saw Sebastian, kneeling beside the bed. His fair hair was still dripping water over his face, and that same plain white towel was still slung around his waist.

Clary sat bolt upright, spinning away from him. "No. Get away from me–"

He caught at her ankle, and jerked. She fell back against the bed, gasping. "Not so fast, little sis," said Sebastian. He shifted into her peripheral vision when he rose to his feet – but he kept hold of her ankle, slowly pulling it back and forth. She wondered if he was going to break her leg, but he just grinned. "Last night was fun, wasn't it? I certainly enjoyed myself–"

"I don't believe you," Clary spat. "What I saw – that wasn't what happened–"

"Wasn't it?" He stared down at her, and she noticed that his eyes were black again, like Valentine's. A moment passed before he released her leg and snorted. "Of course it didn't happen. I might want you, but not like that. I'm not big on incest."

Clary couldn't help a gasp of surprise. She blinked. I might want you. "But – but the dress – the floor–"

"That was when I pulled away." At the startled look on her face, his grin widened. "The majority of it happened. Right up until I tried to tear your dress off and you started screaming." He shrugged, turned away. "The rest I showed you was an illusion. But, tell me, was I good?"

She felt sick to her stomach. "Get out. I hate you."

"Stop lying to yourself, Clary. I'm your brother." He walked toward the door, his eyes locked on her as he moved. "No matter what I do to you, no matter how many times you say you despise me, there will always be a small part of you that loves me because I'm your brother. You can't deny it. That's what it's like for me … with you." He opened the door. "I'll check in on you later. Get some sleep. We're marching to battle at sunrise, to kiss goodbye to your little Shadowhunter friends."

He closed the door quietly behind him, leaving Clary laid across the bed, shaking as the tears came.