Never let it be said that Jace Wayland – Morgenstern, whatever he was – had slack nerves. He was always on edge, always ready, even when sleeping.

Which is why he sat up sharply, eyes narrowed, as he looked out over the dark room.

It was really dark – there was a streetlight halfway down the block, shedding filtered golden glow into the dim room with shelves and shelves of books, lining every available surface. A normal person might have been bewildered at being woken suddenly in a strange place, but Jace was not normal, and he knew exactly where he was.

Luke's house, Clary's room. She was sleeping in the living room.

"I know you're there," he informed the room, fingers curling around the seraph blade he slept with.

"I figured you did," another voice joined his in the gloom. "But do you even know who I am? For that matter, do any of us know who we really are? What is the nature of our existence?"

Jace's fingers uncurled from the blade. "Mundane," he sighed, wearily. "Only you would show up in the middle of the night to talk philosophy with someone who doesn't really particularly feel like talking to you. What are you doing here? And in the middle of the night no less... you do know you can walk around in the daytime, yet?"

"Thanks to you."

Simon stepped from the shadows, hands shoved deep in jean pockets, already thin face thrown into sharper relief by the sparse light. Even though he was across the room, Jace could see the other's eyes peering at him in surprising intensity.

"It was the sword." Jace retorted, as though it was an old argument he was sick of having.

It wasn't, but he was.

Simon shrugged languidly, stepping forward again, leaning against the foot board of the bed. "So you say."

"Ooh... big talker." Jace snorted, rolling his eyes. "What, you lose a heartbeat, and suddenly you become all laconic and sober?"

A flush of borrowed blood flitted on Simon's pale cheeks. "I'm trying something new. Oz."

Jace's eyebrows shot skyward. "You're off to see the wizard?"

"Those cultural references you get," Simon muttered, "But not Whedon? No, I'm trying to be like Oz. The werewolf."

"A vampire trying to be a werewolf, I'm sure Raphael is thrilled."

"He's a character in a tv show," Simon blurted out. "Who was cool. And you don't have to be jealous of Raphael, you know."

"Who's jealous?" Jace frowned. "And why would I be?"

Simon snorted. "Hello, obvious. You're always glaring at him out of the corner of your eyes, your heart rate picks up sharply... you're either in love, or jealous. And I really don't think you love him."

Jace scowled, unimpressed. "Did hatred not penetrate that thick skull of yours?"

"Nope." He said cheerfully. "I know how you react when there's hatred. Your heart slows down, like you were going into some kind of like, trance, and you get all tantric..." he waved his open, disarming, hands. "And your eyes get all intense. Kind of," he smirked, "Like now."

"Because you're irritating." He sighed irritably, crossing his arms and closing his eyes stubbornly.

"So I've heard."

"Go away." Jace demanded, petulantly, eyes still closed.

A sudden breeze whipped his hair and the bed dipped around him, but before even steel-nerved Jace could open his eyes, a murmur in his ear, dry and eerily breathless, said: "No. I want to taste hatred."

He cried out, but it was no use – Simon sunk his teeth into Jace's neck, and Jace cried out, unconsciously clutching at Simon, tugging him closer. Just like the last time he'd fed Simon, there was the startling pain at first, then the creeping, delicious sleepiness that made him want to curl up in Simon's arms and let the undead bloodsucking Mundane boy drain him of his life.

Simon abruptly slid his teeth out of Jace's neck, smirking slightly as he licked his bloody lips, swiping his thumb along the bloody teethmarks. "Guess no one ever really sees the scars, do they, the way you get cut up all the time anyway."

Jace sneered, weakly. "Did you get to taste your hatred?"

Simon considered that, face intense as he considered Jace's neck, and the pale white scares, row upon row.

"No," he said at last, smirking crookedly.

"Then why did you - ?!" Jace exploded.

"Because," Simon explained, slowly as though to a child.

"I tasted addiction."