A/N: A what-if I thought of when re-watching 2x10. What if Valentine had found Alec in the elevator Madzie threw him in? And then things spiraled off from there.

Disclaimer: Not mine. Some lines from episode 2x10 "By the Light of Dawn"; they're not mine, either. Thanks to 29Pieces for beta reading!

Chapter 1: Contingencies Upon Contingencies

The alarm was blaring, red flashing from all the light fixtures, and the message "Wards Breach" displayed boldly on every screen and monitor.

"I thought these wards were airtight," Aldertree demanded.

Alec ignored the useless comment. They'd been breached, and dealing with the threat was more important than grousing about how it happened.

"How many soldiers are here?" he asked, checking his bow as he surveyed the op center. His team of archers assembled behind him.

"Only two dozen. Everyone else is out dealing with the Downworld attacks," Aldertree replied.

Alec had to wonder if that had been the plan all along. Divide and conquer.

"I'll take the entry with Longford."

"We'll cover the weapons room," Aldetree said as their group split.

"Valentine's work?" Longford asked.

"Only one way to find out," Alec replied grimly.

The doors to the foyer suddenly slid open, revealing three shadowhunters sprawled on the floor in the entryway. And in the middle was the last thing Alec had expected to see.

He put his arm out to keep his men back. "Hold your fire."

Longford already had an arrow nocked to his bow, poised to shoot. "What's a little girl doing here all alone?"

"She's a warlock," Alec explained. She must have breached their wards. But why? Was she looking for Clary? Iris Rouse had called upon her blood oath, tasking Clary with finding Madzie. But Madzie was supposedly with Valentine, wasn't she?

Alec cautiously approached her, leery of the fact that there were three shadowhunter guards knocked down in the foyer and that this little girl had just waltzed into the Institute like this. Madzie stepped into the op center, letting the inner doors close behind her.

"Madzie," Alec said carefully. "Did you…?"

She just gazed up at him for a prolonged moment, and then waved her hand. Alec was flung off his feet and through the air into the nearby elevator, the doors closing with a ding. A second later, he could hear the sounds of his men in distress, a discordant chorus of ragged gasping and choking. He pulled himself up and immediately tried to wedge his fingers between the doors to pry them open, but they didn't budge.

"Madzie!" Alec slammed his fists on the doors. "Madzie!"

The sounds outside were dying down, and that filled Alec's heart with a surge of panic. He tried again to pull the doors open. The coughing and gurgling ceased.

No!

"Madzie!" he tried one last time, and punched the door in frustration. She wasn't going to listen to him.

He pushed himself backward and started looking for another way out. Yet before he could reach up to dislodge the ceiling panel and access the escape hatch, the doors dinged and slid open. Alec froze for a split second as none other than Valentine Morgenstern stood before him.

Alec's bow was on the floor, and he made a move to scoop it up, but Valentine was quicker, and had the Soul Sword pointed at his throat before he could reach his weapon.

Valentine looked him up and down. "Ah, the Lightwood boy. My son's parabatai."

Alec swallowed, calculating his chances if he tried to disarm Valentine. But there were several Circle members there with him…and Madzie. Dammit, she was working with them.

Valentine cocked his head at his men, and two stepped forward to seize Alec. He gave a half-hearted struggle on principle, but he was outnumbered. They dragged him out of the elevator, and his stomach dropped at the sight of his team collapsed on the floor, some with vacant eyes open at nothing. Alec snapped his gaze to Madzie, to…what? Silently plead with her?

Valentine apparently noted the look, and his eyes narrowed a fraction as he glanced between Alec and the child.

"Madzie, sweetheart," he said, tone deceptively gentle. "Do you know this shadowhunter?"

Madzie looked up at Alec. She didn't say anything, but there was a hesitant vulnerability in her eyes.

"Is he your friend?" Valentine continued, crouching down beside her.

Alec didn't know what his game was, but he had no intention of playing. "Madzie, he's using you."

Valentine shot him a dark glower, but quickly smoothed it away before turning back to Madzie and reaching out to pat her shoulder. "Tell you what, sweetheart. This young man is also a friend of my son's, and I think it would be a good idea if we made sure he was safe while we take care of things here. What do you say? Will you create a portal so a couple of my men can take him somewhere he'll be safe until we're done?"

Alec's eyes widened. "Madzie, no—"

She gave him a wavering look, and then held her palm out to the side as a portal swooshed into existence.

Alec struggled against his captors, but they had activated their strength runes, and he hadn't yet.

Valentine stood up, gaze hardening again. "Take him to the garage," he instructed. "Oh, and, give him the same special treatment as our other guest."

Alec didn't have a chance to wonder what that meant before he was swallowed up by the portal.

As soon as they exited the other side, Alec tried to throw off his captors. But if he was hoping for better odds, he was sorely disappointed. Valentine had apparently not brought his whole contingent of new shadowhunters to the Institute, and there were several more at whatever hideout this was.

He managed to elbow one Circle member in the stomach, but three more moved forward to help restrain him.

"Hold him still," the one he'd elbowed snarled. "And grab an injection."

Wait, what?

Alec bucked and tried to twist away, but there were too many. One kicked out the backs of his knees, driving him to the ground. Without proper leverage, he was quickly trapped in a headlock by one and his right arm torqued back and up to its breaking point. He let out a strangled cry as the nerve endings pinched.

Valentine's lieutenant marched toward him, holding up a syringe with some kind of black liquid inside. Alec's heart seized.

"No—"

His head was wrenched to the side painfully, exposing his neck. He felt a sharp prick, and then fire splashed into his veins. He choked on a garbled cry as molten liquid crept up his face, spotting his vision and feeling as though it was worming its way into his brain. It burrowed downward, also, his muscles spasming as it overwhelmed him.

"Lock him up."

Alec was released from the headlock and hauled up by both his arms. He couldn't even formulate a thought of fighting back before he was thrown unceremoniously onto cold concrete. There was a rattle of chain links and something was closed behind him. Alec curled up on his side as Valentine's poison began to permeate every cell and slowly dismantle him.

Jace walked right through the doors into the Institute, glamoured as Clary where he was immediately grabbed by two Circle members.

"Tell Valentine I'm here," he bit out sharply while a third patted him down for weapons. He'd come in unarmed, though.

The only weapon he needed tonight was his own blood. Demon blood.

Finally, some good would come from the corruption that ran through his veins. And it didn't matter that touching the Soul Sword and destroying it would kill him, too. It was better that way. Jace would get an honorable death, one worthy of his kind rather than the abomination his father had made of him.

He would take the fate Valentine had cursed him with from birth and fashion something different. Destiny would be on his terms, not Valentine's.

And Clary would be safe; the Downworld would leave her alone after this. As long as she and his family were all right, then this would all be worth it.

Jace held his head high when Valentine strolled out.

"Hello, my dear."

He had to keep up the part he was playing, though, so he struggled uselessly against the shadowhunters holding his arms and demanded in Clary's voice, "Where's Simon? Before I do anything, I need to know he's alive."

"But I'm afraid you may have waited too long," Valentine tsked.

Jace's heart clenched, not for any love lost between him and the vampire, but because Clary cared about him. "Where is he?" he growled.

Valentine smirked, and cocked his head. Jace was released, and he tightened his jaw as he fell into step to be escorted through the Institute. He cast his gaze around the op center and corridors they passed. The bodies of his fallen comrades had been shoved to the sides, but he didn't spot Alec or Izzy. That didn't encourage him so much, though, and Jace had to resist the urge to rub at his parabatai rune.

Valentine led him to Aldertree's office and opened the door, entering first. Jace followed, and pulled up short at the sight of Simon slumped on the couch, head hanging forward as blood trickled slowly from his mouth and the gash on his neck. His entire front was drenched in blood, so much so that there was probably barely left in his body. Slight whistling wheezed from his lips.

"Simon." Jace immediately whipped his gaze to the desk where a letter opener was laid out, and he snatched it up without hesitation. "Hold on, okay?" He crossed the room, sitting next to the vampire and drawing the sharp instrument along his wrist.

"Stay with me, Simon."

They couldn't lose him now. Clary was gonna need someone to look out for her when Jace was gone. But when he held his bleeding wrist to the vampire's mouth, Simon barely stirred.

"Simon, please," Jace urged.

The vampire opened his eyes to slits and just looked at him. Jace knew he was seeing Clary's face…and wouldn't drink from her. Jace would admire that kind of noble resolve if it wasn't currently messing up his plan.

"Come on," he said, practically shoving his wrist into Simon's mouth. "Come on, Simon." Couldn't the vampire smell that Jace's blood had demonic contaminants in it? Maybe his brain was too addled to realize that Jace wasn't actually Clary.

Simon rocked his head back and looked at him again. The stubborn fool.

"Simon, drink," Jace commanded, going for the tone Clary always seemed to use to get her way.

Simon grunted as he shook his head.

"Come on. It's okay. Feed."

"Careful, Clarissa," Valentine spoke up.

Jace ignored him. He was going to save Simon for Clary if it was the last thing he did.

Which, in the back of his mind, he knew shouldn't be the last thing he did. The last thing he needed to do was touch the Soul Sword and destroy it, thereby saving the entire Downworld.

But the moment Simon finally sank his teeth into Jace's wrist, all those thoughts flew away in the wave of sheer ecstasy that flooded through Jace. He threw his head back, overwhelmed by the pure euphoria. A tear slid down his face.

Simon shot a hand up to latch onto his arm, drinking more greedily as survival instinct finally kicked in.

"He's drinking too much," Valentine spoke up.

Jace couldn't bring himself to care.

"Stop him. Stop him!"

Two shadowhunters rushed forward and pulled Simon away. Jace swayed as the vamp's teeth scraped through his shapeshifting rune, and the glamour faded. Simon was panting heavily as his eyes widened on Jace.

Well, so much for carrying that ruse through till the end.

Jace angled an exhausted look up at Valentine, who merely regarded him with a tense expression that wasn't very surprised.

"Shapeshifting, huh?" Valentine smirked. He rolled his eyes. "Well, that's original."

Jace got to his feet. The bliss from the vampire venom, though potent, at least wore off quickly, and he was swiftly regaining his senses. "I learned from the best."

Valentine turned back around. "No, you didn't. I would never willingly let a vampire taste my blood."

Yeah, before today, Jace would never have, either. But hey, his blood was already tainted, so what did it matter?

"Do you have any idea what you've done?" Valentine demanded angrily.

"I saved a life," Jace rejoined. And that, he was not ashamed of, no matter the method.

"A monster's life," Valentine countered. "And for what? He's just gonna die with the rest of the Downworld, anyway."

Not if Jace had anything to say about it. Yet before he could formulate a new plan, Simon suddenly lunged from the couch, tackling Valentine with vampire speed and knocking him to the ground. Valentine's sword clattered across the floor, and Jace quickly snatched it up. He whirled on the two guards, ducking under one's swing and slicing through the second.

Pivoting, he locked blades with the first, grunting as each struggled for the upper hand. But Jace was better trained than these new shadowhunters who'd only been created a few weeks ago. He grabbed the man's arm to keep his sword at bay while sliding his blade away and slashing his stomach. Jace then followed through with a thrust into the heart.

He let the body drop and went to the wall where a decorative knife was mounted. Plucking it from its display, he shouted at Simon. "Here!"

Simon caught the toss easily.

"We have to destroy the sword," Jace said, turning for the door. "Come on."

Apprehending Valentine wouldn't be enough, and so Jace left the man temporarily knocked out on the floor. Destroying the Soul Sword was of the utmost importance, to end this once and for all.

"Nice moves back there," he said over his shoulder.

"Thanks," Simon replied. "I've been practicing."

Jace would have rolled his eyes, but he was too focused on carefully making his way through the Institute. Valentine would have had more Circle members spread out, so they needed to be on guard. His heart hammered with anticipation, both for what he knew he had to do, and at the hope that he would find Alec and Izzy and they'd be okay.

He finally let himself spare a sliver of attention for his parabatai rune. It wasn't gone, so Alec wasn't dead. But there was something…earlier, Jace had thought maybe his own emotions were too high-strung for him to sense anything clearly, but now it felt…not weakened, but blunted. Maybe Alec was unconscious somewhere, which did not bode well for Jace's nerves, and he was left torn between abandoning his mission to find his brother, and seeing it through, even though it would mean his death.

"Hey, about, you know," Simon spoke up quietly. "What happened back there…"

Jace was only half listening as he rounded a corner and pressed himself up against the wall. Out in the War Room, part of the assembly area had been cleared and what looked like a generator set up in the middle of the floor with a bunch of cables connected to it. And inside it was the Soul Sword, wreathed in sizzling waves of stored electricity.

"I've heard of blood thirst, even felt it," Simon rambled on. "But…never that badly. Once I started feeding, I couldn't stop. I'm really sorry."

Jace shook his head as he finally turned to face the vampire. "Don't apologize."

"I would have killed you," Simon said, and there was such genuine remorse and regret in his eyes that made him more human than Valentine ever was, even with the blood smeared all down his neck in macabre grotesqueness. He didn't just lament the idea that he could have bled Clary dry; Simon Lewis was grieved by the idea of doing that to anyone.

Moisture pricked at Jace's eyes. "I would have let you," he confessed. In that moment of euphoria, there had been no more pain, no more weight of the burden he carried as Valentine's son, as his failed experiment. Jace could have slipped away on a river of peace and been done with it all.

At least Valentine's sense did save him from making that mistake. Jace turned his attention back to the shadowhunters guarding the sword.

"You, like, rescued me from actual death," Simon went on. "So, thanks. A lot."

"Hey, you know how you can thank me?" Jace interrupted. "Shut up."

Simon blinked. "Right."

They both peered into the War Room.

"Looks like they have the sword tapped into that power thing."

"Not for long," Jace assured him. He pulled out his phone to send the signal for everyone to get ready. Once done, he shoved his cell back into his pocket, and noticed Simon leaning too far out to get a look.

"Hey," he hissed, nudging him back out of view. What he wouldn't give for Alec to be at his back. "You know how to use that?" Jace asked, flicking a pointed look at the knife.

"Yeah, just point and stab, right?" Simon replied, jabbing the blade at him.

Jace glanced down at the knife and tried to hold back a sigh. He pushed the blade away with his finger. "Use your vamp speed."

"Obviously."

Jace shook his head. "As soon as we get back up, we move in."

Simon's eyes widened. "It might be too late for that."

Jace peered around the corner in alarm as he saw Valentine dragging Clary into the War Room. "No." Dammit, what was she doing here? That wasn't part of the plan!

"Let me go!" Clary yelled. "No. You can't make me do this."

Jace yanked his phone back out and slapped Simon's arm. "Go." He typed out a hasty text to Luke, letting him know they had to come in, now.

He heard the cries of the Circle members as Simon slew them. Guess practicing those moves had paid off, after all.

Jace took a deep, steadying breath, and marched into the War Room. Simon had Clary and was already escorting her out, but she pulled up short as Jace passed them.

"Jace. What…?"

He ignored her, striding right up to the Soul Sword and dropping his seraph blade with a clang.

"Jace, what are you doing?"

He swallowed hard, wondering if it would hurt.

"Jace!" Clary shouted, and he couldn't help but turn around to look at her. There were tears in her eyes as they pleaded with him. She shook her head. "Don't. If you touch the sword, it'll kill you."

His own eyes watered. Out of everything he was facing, seeing that kind of pain on Clary's face was one of the worst to bear. But he had to do this. He turned back to the sword.

"Jace, don't do it! No, Jace!"

He gripped the hilt and wrenched the blade free. But instead of the sword shattering or disintegrating into dust, it began to glow. Jace's eyes widened with confusion a split second before his blood ignited with a bolt of energy and he was thrown backward with a jolt that flung him into darkness.