Awkwardness was something she hadn't anticipated. Nerves, maybe, and perhaps some uncertainty- the two of them hadn't really been in bed properly for some time- but not awkwardness. Then again, if Simon had, as she had suspected, only agreed to this as a favour to her, then it was to be expected.

She looked over at him beside her, in jeans and a faded black T-shirt that read: I'M NOT THE MESSIAH, I'M A VERY NAUGHTY BOY, in curling white letters. It was one of the few movie quotes she recognized, though the amusement was somewhat lost on her at present. She was herself wearing one of Simon's button-down shirts over her underclothes that he had insisted on lending her.

Feeling she ought to start proceedings- it had been her idea, after all- she rolled awkwardly against him, draping an arm across his side. She was aware, with a small sense of horror, that one of her nails was digging into his leg. She shifted slightly, moving to kiss him, and at the same moment so did he, and her forehead bounced off his.

"Ow!" she said indignantly. "Shouldn't you be better at this?"

She saw a look of some surprise cross his face. "Why?"

She moved forwards, a little tentatively. Before she knew it she was speaking again. "All those nights you've spent in Clary's bed, wrapped in your beautiful platonic embraces." These were exactly the words she had been trying to avoid saying, but it was useless. She would have brought it up sooner or later, and better it happened now, when the arrangement was still almost active. "I kind of figured…"

Simon looked genuinely shocked. "We just slept." He looked as if he wanted to say more, though he was silent, waiting for her to speak again.

"I know," she said. And she was surprised to find that she did know. Perhaps she had known all along, without having to be told. Perhaps he really was interested in her. "But I don't just sleep. With anybody. I don't stay the night usually at all. Like, ever." Silently she cursed herself for saying so much. It couldn't be doing wonders for his confidence.

He seemed a little taken aback. "You said you wanted to-" he began.

"Oh, shut up," she told him, and leaned across to kiss him. It was all she could think to do. This part, at least, she could cope with. Verbal reassurances and soppiness weren't her forte, but when she was kissing Simon, instinct took over. His lips were cold, as she had expected, but he kissed her back without question, hands moving through her hair. She moved into his lap, twining her arms round his neck- and without warning he pulled back, an odd expression on his face.

"Now what is it? You don't want to kiss me?" she asked. But she knew it was more than that. It had taken her a moment, but she had read his expression. Self-loathing.

"I do," she heard him say, his voice slightly muffled. Something glinted at his lower lip. Isabelle made out, with a sense of dawning realization, the shape of his fangs protruding from his gums.

"Oh," she said, more to herself than to him. "You're hungry." She looked at him. "When was the last time you had any blood?"

She heard him murmur "Yesterday," but it was unclear. She was only partly listening. An idea was taking shape in her mind, something she had been wondering about for the last few weeks. She would never have acted on it until tonight, but still…

"Maybe you should feed yourself," she said quietly. She sat back against one of Magnus' pillows. "You know what happens if you don't."

He looked disappointed, in himself mainly. "I don't have any blood with me. I'll have to go back to the apartment." She saw him breathe in deeply, and his fangs disappeared from view. He started to get up, and on an impulse Isabelle caught his wrist, keeping him there.

"You don't have to drink cold animal blood," she said. The idea had taken hold of her. It wasn't just something she was prepared to do now. It was something she wanted to do. "I'm right here."

She saw his dark eyes widen. "You're not serious," he said weakly.

"Sure I am." She reached for the buttons on her shirt- his shirt, really- and started to undo them. She swept her hair back over her shoulder. "Don't you want…?"

He caught at her wrist. He seemed desperate. "Isabelle, don't." His voice was pained. He seemed to be deliberately trying not to look at the vein in her throat. "I can't control myself, can't control it. I could hurt you, kill you."

She looked at him, seeing the worry on his face, trying to think of how to reassure him. "You won't. You can hold yourself back. You did with Jace."

"I'm not attracted to Jace." His expression was one of concern, though she couldn't help smiling slightly.

"Not even a little?" she said. "Eensy bit? Because that would be kind of hot. Ah, well. Too bad. Look, attracted or not, you bit him when you were starving and dying and you still held back."

He didn't seem convinced. "I didn't hold back with Maureen," he said, with another hint of self-loathing. "Jordan had to pull me off."

"You would have." She had been picking at a loose button on the shirt she was wearing. Now she touched her finger to his lips, cutting off whatever comeback he had, and allowed it to drift down towards his unbeating heart.

"I trust you," she said. And she was amazed to find that she did. People didn't win her trust over quickly. And they often didn't hold onto it for very long. But Simon was different. Even if she hadn't felt the way she did- and she wasn't even sure how that was anymore- he exerted an air of trustworthiness that few people she had met did.

He shook his head. "Maybe you shouldn't."

"I'm a Shadowhunter. I can fight you off if I have to."

"Jace didn't fight me off."

"Jace is in love with the idea of dying," she reminded him. "I'm not." She wrapped her legs around him and slid across the bedspread. She was close enough that, had he been alive, she would have felt him breathing. He leaned forwards, reluctantly perhaps, and kissed her tentatively, for a moment, but drew back quickly, seeming a little panicked.

"Isabelle, I can't." He looked distressed, the pupils of his eyes dilated. "I don't want you to see me like this."

She felt something stinging at the backs of her eyes. Tears. Impatiently she pushed them down. One of them needed to be strong right now and it was clear it wasn't going to be him. She touched his cheek lightly. "Simon," she said, "this is who you are-"

He exhaled, needlessly, purely out of frustration at himself rather than any need for oxygen. "You can't possibly want this," he said, sounding depressed. He ran a hand over his face and up through his hair. "You can't possibly want me. My own mother threw me out of the house. I bit Maureen- she was only a kid. I mean, look at me, look what I am, where I live, what I do. I'm nothing."

He had turned away from her as if unwilling to look at her. With shock she realized he was starting to believe the things he had just said. More than that, he believed the things were set in stone, that he couldn't change them. "You're not nothing," she said. "Simon. Please. Let me see your face."

He turned his head slightly to look at her. She turned her wrist slightly, exposing more clearly the traceries of white scars on her skin. "Look at these," she said. "Ugly, aren't they?"

His face morphed to an expression of disbelief. "Nothing about you is ugly, Izzy."

"Girls aren't supposed to be covered in scars," she persisted. "But they don't bother you."

He was growing more and more shocked. "They're part of you," he said, almost with indignation on her behalf. "No, of course they don't bother me."

She leaned in closer to him. Her finger traced the shape of his lips. "Being a vampire is part of you," she whispered. Before she knew it words were tumbling out of her in a rush. "I didn't ask you to come here last night because I couldn't think of anyone else to ask. I want to be with you, Simon. It scares the hell out of me, but I do."

She looked at him closely, fearing she had gone too far, asked for too much. She could feel the backs of her eyes burning. But his face lit up- a reassurance no words could match- and before she knew it he was kissing her again, and she was pressed up against him, and then suddenly she was on top of him, and he was pulling her down to lie against him. She whispered quietly to him, again, that she wanted to be with him, that who he was mattered more than what he was, though her words were lost in the moment they shared, overridden by a far more powerful yet mute feeling. He kissed her again, deeper this time, and a small gasp escaped her lips, her fingers digging into his hair, and then he sat up slightly and put his left arm around her waist, and before she knew what was happening she was rolling across the covers, and suddenly she was under him, feeling his body pressed against hers, and she forgot her worries, forgot that Jace and Clary were gone, forgot that Azazel could not help them, forgot everything…

Then Simon tensed on top of her, and she sensed that he wanted to roll away, to shut down his instincts, and she locked legs around his, keeping him on top of her.

"Go ahead," she heard herself say. His eyes were dark, staring down into hers from a few inches away. "I want you to." Her heart was racing- he could surely feel it against his chest, could surely see her pulse beating in the side of her throat.

His eyes closed; he was breathing deeply, unnecessarily. "No."

She turned her head slightly, raising herself off the pillows. She would have kissed him again, but she could see his fangs flashing in the darkness, and held back. "I want you to."

He blinked down at her. She could see fear in his eyes- not for himself. Of himself.

"Aren't you scared?" he whispered.

"Yes," she admitted. "But I still want you to."

"Isabelle- I can't-"

She opened her mouth, intending to say something further, perhaps a joke about his masculinity- and gasped as his fangs slid into the vein of her throat. She had expected pain, been prepared for it, but what she hadn't been expecting was the feeling of loss, loss of focus, loss of concentration, all of her senses attuning purely to the feeling in her neck. Her heart was thundering wildly against her ribcage; she arched up against Simon, her head tilting back, her fingers sliding through his hair, gripping with perhaps a little too much force, for he slowed slightly, watching her with worry, and she tried to tell him with her eyes to keep going, for she felt if she spoke, her voice would surely betray her. His eyes were dilated, fixed on her, and he seemed to get the message, re-adjusting himself, fangs digging deeper. His eyes closed, and she sensed that even as she felt her mind slowing, her body focusing only on the painful yet pleasurable sensation, his senses were heightening, his inhibitions were fading, almost as if he were alive-

His fangs slid out of the vein in her throat. She inhaled sharply with surprise, and he rolled off her, panting almost in unison with her. She tried to turn her head, but her body didn't seem to be obeying her. Her chest was rapidly rising and falling, blood trickling slowly out of the side of her neck.

"Izzy…" she heard Simon whisper.

"What?" she said, relieved to find that her voice was under control.

"You didn't stop me." He sounded hopeful, and maybe a little concerned.

"I didn't want to," she said, honestly.

She heard the creak of bedsprings, and turned her head slightly to see Simon leaning across to her. Lightly he kissed the puncture marks in her throat, cleaning the blood away. She felt a shock run through her, and again found herself speaking. "Simon…"

He drew back, looking at her nervously, and perhaps a tad hopefully. She reached out to stroke his hair. "I…"

"What?"

She didn't know what she would have said, but at that moment she yawned, surprising herself as much as him, she thought, and hooked her finger through one of his belt loops. She didn't have an explanation for this- she had been alert mere minutes ago- but Simon's expression instantly changed.

"Are you okay?" he said, sounding upset. "Did I drink too much? Do you feel tired? Are-"

She scooted over to him. "I am fine. You made yourself stop. And I'm a Shadowhunter. We replace blood at triple the rate a normal human being does."

"Did you…" he began, looking apprehensive. He finished the sentence awkwardly. "Did you like it?"

Isabelle nodded lazily. "Yeah," she said, quite truthfully. "I liked it."

He seemed surprised. His eyebrows went up, and she found herself smiling at his expression. "Really?"

She giggled a little. "You couldn't tell?"

"I thought maybe you were faking it."

She propped herself up, looking down at him. "I don't fake things, Simon. And I don't lie, and I don't pretend."

He smiled, a little tentatively. "You're a heartbreaker, Isabelle Lightwood." His pupils were still dilated, though slowly returning to normal. "Jace told Clary once you'd walk all over me in high-heeled boots."

She eyed him. "That was then. You're different now. You're not scared of me."

He reached out to cup her cheek. "And you're not scared of anything."

She saw his expression, and couldn't resist. "I don't know," she said. "Maybe you'll break my heart." She kissed him quickly, before he could say anything. She wasn't sure if she could handle his response either way. "Now shut up. I want to sleep." She curled up against his body, closing her eyes. She was awake just long enough to notice that, somehow, they fit together now, as if more familiar with each other. Then the world darkened, and she was asleep.