Isabelle had spent most of the day with Simon around Central Park. It was late when they returned to the Institute to get ready for the party, and even later still when they left for it again. The directions on the invitation took them to a largely industrial neighborhood in Brooklyn whose streets were lined with factories and warehouses. Some had been converted into lofts and galleries, but there was still something forbidding about their looming square shapes, boasting only a few windows covered in iron grilles. They made their way from the subway station, Isabelle navigating their way with the Sensor. Simon was absolutely fascinated, either with the Sensor or her. (Probably her, because she looked fabulous. She wore her clothes better than Clary, although Isabelle felt she'd done a pretty good job of dressing the other girl up.)

The right street seemed to be a narrow avenue lined with old warehouses, though most now bore the signs of human residence: window boxes filled with flowers, lace curtains blowing in the clammy night breeze, numbered plastic trash cans stacked on the sidewalk. When they came up to a bunch of obviously vampire-owned motorbikes – altered to run on demon energies, giving them an air of being a living thing – Isabelle knew had to be in the right place. So of course Jace insisted on fiddling with the bikes, for an unknown reason.

"Hurry up," Isabelle complained. "I didn't get this dressed up to watch you mess around in the gutter with a bunch of motorcycles."

"They are pretty to look at," said Jace, hopping back up on the pavement. "You have to admit that.

"So am I," said Isabelle, who didn't feel inclined to admit anything. "Now hurry up."

Jace was looking at Clary. "This building," he said, pointing at the red brick warehouse. "Is this the one?"

Clary exhaled. "I think so," she said uncertainly. "They all look the same."

"One way to find out," said Isabelle, mounting the steps with a determined stride. The rest of them followed, crowding close to one another in the foul-smelling entryway. A naked bulb hung from a cord overhead, illuminating a large metal-bound door and a row of apartment buzzers along the left wall. Only one had a name written over it: BANE. Isabelle pressed the buzzer. Nothing happened. She pressed it again. She was about to press it a third time when Alec caught her wrist. "Don't be rude," he said.

She glared at him. "Alec –"

The door flew open. A slender man standing in the doorway regarded them curiously. It was Isabelle who recovered herself first, flashing a brilliant smile. "Magnus? Magnus Bane?"

"That would be me." The man blocking the doorway was as tall and thin as a rail, his hair a crown of dense black spikes. He wore jeans and a black shirt covered with dozens of metal buckles. His eyes were crusted with a raccoon mask of charcoal glitter, his lips painted a dark shade of blue. He raked a ring-laden hand through his spiked hair and regarded them thoughtfully. "Children of the Nephilim," he said. "Well, well. I don't recall inviting you."

Isabelle took out her invitation and waved it like a white flag, still with a winning smile. "I have an invitation. These –" She indicated the rest of the group with a grand wave of her arm. "– are my friends."

Magnus plucked the invitation out of her hand and looked at it with fastidious distaste. "I must have been drunk," he said. He threw the door open. "Come in. And try not to murder any of my guests."

Jace edged into the doorway, sizing up Magnus with his eyes. "Even if one of them spills a drink on my new shoes?"

"Even then." Magnus's hand shot out, so fast it was barely a blur. He plucked the stele out of Jace's hand and held it up. Jace looked faintly abashed. "As for this," Magnus said, sliding it into Jace's jeans pocket, "keep it in your pants, Shadowhunter." Magnus grinned and started up the stairs, leaving a surprised-looking Jace holding the door.

"Come on," he said, waving the rest of them inside. "Before anyone thinks it's my party."

They pushed past Jace, laughing nervously. Only Isabelle stopped to shake her head. "Try not to piss him off, please. Then he won't help us."

Jace looked bored. "I know what I'm doing."

"I hope so." Isabelle flounced past him in a swirl of skirts.

-----

Magnus's apartment was at the top of a long flight of rickety stairs. The loft itself was huge and almost totally empty of furniture. Floor-to-ceiling windows were smeared with a thick film of dirt and paint, blocking out most of the ambient light from the street. Big metal pillars wound with colored lights held up an arched, sooty ceiling. Doors torn off their hinges and laid across dented metal garbage cans made a makeshift bar at one end of the room. A lilac-skinned woman in a metallic bustier was ranging drinks along the bar in tall, harshly colored glasses that tinted the fluid inside them: blood red, cyanosis blue, poison green. Even for a New York bartender she worked with an amazingly speedy efficiency – probably helped along by the fact that she had a second set of long, graceful arms to go with the first.

Jace and Alec disappered into the crowd with Clary, trying to corner their warlock host for a chat. Meanwhile, Isabelle immediately dragged Simon onto the dancefloor. He wasn't a very good dancer. In fact, he mostly kept bouncing up and down on the balls of his feet, looking uncomfortable. Didn't matter, Isabelle could slink in a circle around him, trailing her fingers across his chest. For a while, it was surprisingly hard not to think about dancing with someone else somewhere else, but once she started visiting the bar, it got much easier to forget and focus. Good enough to lean against Simon for support when she stumbled, and laugh in his ear. This seemed to please him.

In fact, it pleased him so much that even though he said he wasn't much of a drinker, he ended up making his way to the bar anyway. Isabelle took her time trailing there after him – had to indulge in a moment of dancing with a faerie with leaf green eyes – and by the time she got there he was already holding a bright blue drink. It was one Isabelle recognized, and she frowned at it.

"Simon, you shouldn't drink that," she said. Only slurring her s's a little bit.

He looked confused. "Why not? They said it was good."

"It's a fair folk drink." Honestly, mundanes. "You can't drink it, it's not good for you."

Simon gave his drink a critical look, then shook his head. "What could a drink do to me, Isabelle? I can definitely take it." And although Isabelle protested, he went and took a big gulp of the unnaturally blue liquid. And then... He seemed to almost shimmer. And then he turned suddenly smaller.

Into a rat on the floor.

"Simon!"

He ran under the bar. Isabelle tried to kneel and call for him, but it was no use. And she couldn't – and didn't want to – properly kneel in her dress for a stupid mundane turned into a rat, either, so she clambered back to her feet to find the others.

Which took way too long, if you asked her. She couldn't really entirely focus on what she was seeing, and she kept bumping into people, trying to work her way through the crowd. And then with some weird mix of guilt and anger washing over her, it wasn't great. It wasn't until Alec called her name and waved her over that she found them. He also yelled for her to 'watch out for the phouka', but she still completely ignored the thin brown-skinned man in a green paisley vest who eyed her thoughtfully as she walked by. She had other things on her mind. "Where have you been?" she exclaimed as she got to the others. "I've been looking all over for you!"

"Where's Simon?" Clary interrupted.

Isabelle wobbled. "He's a rat," she said darkly.

"Did he do something to you?" Alec was full of brotherly concern. "Did he touch you? If he tried anything –"

"No, Alec," Isabelle said irritably. "Not like that. He's a rat."

"She's drunk," said Jace, beginning to turn away in disgust.

"I'm not," Isabelle said indignantly. "Well, maybe a little –" A lot. "– but that's not the point. The point is, Simon drank one of those blue drinks – I told him not to, but he didn't listen – and he turned into a rat."

"A rat?" Clary repeated incredulously. "You don't mean..."

"I mean a rat," Isabelle said. "Little. Brown. Scaly tail."

"The Clave isn't going to like this," said Alec dubiously. "I'm pretty sure turning mundanes into rats is against the Law."

"Technically she didn't turn him into a rat," Jace pointed out. "The worst she could be accused of is negligence."

"Who cares about the stupid Law?" Clary screamed, grabbing hold of Isabelle's wrist. "My best friend is a rat!"

"Ouch!" Isabelle tried to pull her wrist back, shocked that Clary would even grab her like that. It was probably her intoxication that made her attempts at freeing herself futile. "Let go of me!"

"Not until you tell me where he is." She was glaring at Isabelle like she wanted to slap her. "I can't believe you just left him – he's probably terrified –"

"If he hasn't been stepped on," Jace pointed out unhelpfully.

"I didn't leave him. He ran under the bar," Isabelle protested, pointing towards the bar with her free hand, then tugging her other hand back again. "Let go! You're denting my bracelet."

"Bitch," Clary said savagely, and flung Isabelle's hand back at her, hard. Isabelle made a surprised noise despite herself, as Clary ran for the bar. Dropping to her knees, she peered into the dark space under it. Jace and the others arrived behind her, Isabelle feeling a mess of annoyance and anger and that irritating guilt again. She felt like glaring at everyone.

"Is he under there?" Jace asked curiously.

Clary, still on her hands and knees, nodded. "Shh. You'll frighten him off." She pushed her fingers under the edge of the bar. "Please come out, Simon. We'll get Magnus to reverse the spell. It'll be okay." A second later, she exclaimed in relief, seizing the rat in her hands. "Simon! You understood me!" The rat, huddled in the hollow of her palms, squeaked glumly. Delighted, she hugged him to her chest. "Oh, poor baby," she crooned, almost as if he really were a pet. "Poor Simon, it'll be fine, I promise –"

"I wouldn't feel too sorry for him," Jace said. "That's probably the closest he's ever gotten to second base."

"Shut up!" Clary glared at Jace furiously, but she did loosen her grip on the rat. His whiskers were trembling, whether in anger or agitation or simple terror, she couldn't tell. "Get Magnus," she said sharply. "We have to turn him back."

"Let's not be hasty." Jace was actually grinning. He reached toward Simon as if he meant to pet him. "He's cute like that. Look at his little pink nose."

Simon bared long yellow teeth at Jace and made a snapping motion. Jace pulled his outstretched hand back. "Izzy, go fetch our magnificent host."

"Why me?" Isabelle asked, feeling petulant. She just wanted to go home.

"Because it's your fault the mundane's a rat, idiot," he said, and Clary was struck by how rarely any of them, other than Isabelle, ever said Simon's actual name. "And we can't leave him here."

Isabelle scowled a him, wobbling in place. "You'd be happy to leave him if it weren't for her," Isabelle said, managing to inject the single syllable word with enough venom to poison an elephant. She stalked off, her skirt flouncing around her hips. Magnus wasn't far away, and she all but dragged him back to the others.

"Rattus norvegicus," Magnus said, peering at Simon. "A common brown rat, nothing exotic."

"I don't care what kind of rat he is," Clary said crossly. "I want him turned back."

Magnus scratched his head thoughtfully, shedding glitter. "No point," he said. "That's what I said." Jace looked pleased. "No point?" Clary shouted, so loudly that Simon hid his head under her thumb. "How can you say there's no point?"

"Because he'll turn back on his own in a few hours," said Magnus. "The effect of the cocktails is temporary. No point working up a transformation spell; it'll just traumatize him. Too much magic is hard on mundanes, their systems aren't used to it."

"I doubt his system is used to being a rat, either," Clary pointed out. "You're a warlock, can't you just reverse the spell?"

Magnus considered. "No," he said.

"You mean you won't."

"Not for free, darling, and you can't afford me."

"I can't take a rat home on the subway either," Clary said plaintively. "I'll drop him, or one of the MTA police will arrest me for transporting pests on the transit system." Simon chirped his annoyance. "Not that you're a pest, of course."

A girl who had been shouting by the door was now joined by six or seven others. The sound of angry voices rose above the hum of the party and the strains of the music. Magnus rolled his eyes. "Excuse me," he said, backing into the crowd, which closed behind him instantly.

Isabelle, wobbling on her sandals, expelled a gusty sigh. "So much for his help."

"You know," Alec said, "you could always put the rat in your backpack."

Clary looked at him hard, but apparently couldn't find anything wrong with the idea, since she went with it. Shrugging off her pack, she found a hiding place for the small brown rat that had once been Simon.

"I'm sorry," she told him miserably.

"Don't bother," Jace said. "Why mundanes always insist on taking responsibility for things that aren't their fault is a mystery to me. You didn't force that cocktail down his idiotic throat."

"If it weren't for me, he wouldn't have been here at all," Clary said in a small voice.

"Don't flatter yourself. He came because of Isabelle."

Oh, good, now Isabelle didn't have to say it. Angrily Clary jerked the top of the bag closed and stood up. "Let's get out of here. I'm sick of this place."

-----

Outside on the street, Isabelle walked with Alec ahead of Clary and Jace. She wasn't even sure why, but she felt angry and inconsolable, and still more than a little drunk. She kept having to wipe at her eyes.

"It's not your fault," Alec was saying. He sounded weary. "But it ought to teach you not to go to so many Downworld parties," he added. "They're always more trouble than they're worth."

Isabelle sniffed loudly. "If anything had happened to him, I—I don't know what I would have done."

"Probably whatever it is you did before," said Alec in a bored voice. "It's not like you knew him all that well."

"That doesn't mean that I don't –"

"What? Love him?" Alec scoffed, raising his voice. "You need to know someone to love them."

"But that's not all it is." Her voice sounded small. Sad. "Didn't you have any fun at the party, Alec?"

"No."

"I thought you might like Magnus. He's nice, isn't he?"

"Nice?" Alec looked at her as if she were insane. "Kittens are nice. Warlocks are –" He hesitated. "Not," he finished, lamely.

"I thought you might hit it off." Isabelle's eye makeup glittered as bright as tears as she glanced over at her brother. "Get to be friends."

"I have friends," Alec said, and looked over his shoulder, almost as if he couldn't help it, at Jace.

"Not like that!" Isabelle snapped, far more forcefully than either of them had expected her to. "I don't mean a friend like Jace. That's not what I meant. God."

Poor Alec looked surprised. "Izzy –"

Isabelle waved him a way with a harsh gesture of one hand. "No, leave me alone."

"Iz –"

"I said leave me alone!"

She stalked off, and couldn't decide whether she was sad or happy that he didn't seem to even try to follow her. So, she just kept walking. The tears were really coming down her cheeks again, now. And when she got her phone out, she had to stop to wipe at her eyes just to actually see the screen clearly enough to pick a number. And then she brought the phone to her ear, her bottom lip still trembling a little.

[ooc: NFB, to be continued in the comments with he who knows who he is! City of Bones with editing, yadda yadda.]