Battered, bruised, and terrified, I had finally made it to what appeared to be the source of the demons. My aim on the catwalks had started out bad and had only gotten worse as I grew increasingly more tired. Once my Light magic lamp had sputtered out and I'd had to recast it using only the sheer force of my will. But it didn't matter how many deep muscle bruises I was in denial about, I had made it.

I shoved the door to the room and was pleased to find that it did actually open. Thank goodness. Inside the room – what had clearly once been some sort of machine room (judging by the machines shoved to the edges) – there was a surprisingly large open space in the center. There was a trail of bloodstains on the floor that led from the door over to four large basins; two were stained with blood that had since evaporated, one was filled with blood, and the fourth was still shiny and clean. I stared at the blood. It was Simon's blood.

Simon's blood didn't work, I realized. That's why it was still in the basin. My inadvertent spell at his graveside had preserved enough of his humanity that his blood didn't truly count as "vampire" blood. What exactly that categorized Simon as… well, that I didn't know.

And then I saw it. The Mortal Sword was resting on a table, completely unguarded. I knew enough from my lessons in the Seelie Court that as an individual very strongly aligned with Light magic, I wouldn't be able to touch the sword in its partially altered state for very long without being killed. But I also was full of tricks and one in particular came to mind.

Quickly, I crossed the room and stood over the sword, one hand hovering over it and the other resting on the scabbard that hung at my side. The words felt hot as they left my mouth and for a moment I was afraid I would be burnt, but I didn't stop. Somewhere above me, I heard the leathery flap of wings and knew I was running out of time.

The moment the sound of the last rune left my lips, I felt the greater portion of my strength going with it. This wasn't just some little trick, it had taken a lot of effort. Especially since it had to be good enough to fool Valentine. I took one step back towards the door when my exhausted legs gave out underneath me. I sank to the floor, body utterly spent but mind still sharp. And there I stayed as a demon descended through a hole in the ceiling and gently deposited Valentine and Clary just feet away from me.

I saw Valentine's eyes flick to me and then to where the Mortal Sword sat, undisturbed on its table. And then, I saw him smile.

Someone grabbed the back of Jace's shirt while he still stood at the railing and then turned him around.

"You're alive," Alec said, his voice colored with relief and his face showing every sign of exhaustion.

"So are you," Jace pointed out. He then shoved Alec out of the way in order to stab a charging Drevak demon, but Alec got to it first with his guisarme. "Nice weapon."

"What did you just throw over the edge of the ship?" Alec asked, ready to fight beside his parabatai.

"The Inquisitor."

"Was she…?"

"Dead? No, just wounded."

A muscle in Alec's jaw twitched and he flipped the guisarme in his hands. "She deserves it."

"Alec! Jace!" And then Isabelle was upon them in a whirl of dark hair and electrum whip. She, like her brothers, was covered in blood and ichor. She gave Jace a hug. "Jace, we thought you might be…"

"I'm not," he interrupted. And then frowned as a thought struck him. "But Jaci might be. She and Caelia went down into the ship ages ago. I haven't seen either of the since."

"Jaci's not dead," Isabelle said with confidence. "I would know it if she were."

"They're parabatai now," Alec explained.

"You were right," Isabelle said with a smile. "The ceremony broke the Seelie Queen's hold on her."

"Isabelle!" But they had been too caught up in their conversation and Jace's shouted warning was a second too late.

A spider demon reared up behind Isabelle, poison spraying from its fangs. Isabelle cried out as the poison hit her but immediately used her whip to slice the demon in half. She watched it vanish before stumbling forward for the rail, clutching at her throat.

"Let me take care of her," Alec said, already dropping his weapon. "Hold off whatever comes while I heal her."

Jace stared at his adopted siblings. Normal families didn't have to go through things like this, he thought. "We have to get her off the ship. If she stays here-"

"She'll die, just like the rest of us," Alec interrupted grimly, drawing an iratze as quickly and gently as he could. "There are too many demons, we're being slaughtered. The Inquisitor deserved to die for this – this is all her fault."

"She saved my life," Jace said softly.

Alec blinked in amazement. "Jace, behind you – two of them."

Jace barely had time to take in the two approaching demons, a Ravener and a Drevak, before he'd thrown his last seraph blade. It arched through the air, severed the Ravener's tail which caused it to release its venom all over the Drevak demon and the ship's deck. Jace watched in satisfaction as both demons collapsed and were gone.

"Jace," Alec said, supporting Isabelle who was pale but still breathing and no longer bleeding. "We need to get her out of here."

Jace had taken a step forward to retrieve his seraph blade and as he turned to answer his parabatai, the deck gave out from underneath him and he was falling through the dark interior of the ship.

He landed with a bone jarring thud on a metal catwalk. Inches from his nose, he could just barely make out something glinting. Gingerly, he pulled his witchlight out of his pocket and it flared to life.

The glinting thing was a stele. He stared at it for a moment, wondering if he'd managed to hit his head hard enough during his fall that he was hallucinating. But he knew better than that. As far as he knew, only two Shadowhunters aside from Valentine had gone inside the belly of the ship; therefore, the stele either blonged to Clary or Jaci.

He pushed himself into a sitting position and examined the stele closely. It was an older style, more like the Maryse's stele than his own, and it lacked the slight green sheen Jaci's stele had taken on. That meant it had to be Clary's. Jace spun the stele through his fingers before sliding it into the safety of his pocket. Wherever Clary was, she was going to appreciate getting that back.

The temperature seemed to be dropping and his breath escaped his mouth in little clouds. His shoulder had started to burn and somewhere down the catwalk, a dark figure laughed softly.

Jace closed his eyes briefly. He was without a weapon, possibly concussed, and sitting down. It clearly wasn't an ideal situation but he would have to make the best of it.

His eyes flew open and he hauled himself to his feet, wrenching free part of the railing to use as a weapon. Fortunately, the length of pipe had broken off with a jagged edge. It wasn't perfect, but it would work to face the demon he knew was coming: Agramon.

This time, the demon wore Valentine's face.

Jace didn't have time to chat. The Mark on his shoulder was burning. He hefted the bit of pipe, holding it like a javelin and launched it straight at the demon's chest. The pipe found its target and the great demon of fear could only hiss as its body turned to ash.

Jace picked up the pipe from the ashes, rather pleased with himself and made his way toward the end of the catwalk and to the ladder that led down to the next level. The next catwalk didn't seem particularly helpful either so Jace began to descend another level but stopped, seeing something reflect the witchlight other than the metal.

Blood.

Holding the pipe aloft, Jace set off after the trail of blood, the rune on his shoulder still burning.

There was something strange about the blood, Jace noticed. He couldn't describe it, but there was something slightly off about it. Shaking that feeling, he started to move faster along the catwalk. The patches of blood were becoming more frequent and he found himself faced with a door that had a smeared, bloody handprint streaked across it.

Placing his witchlight in his pocket, Jace carefully swung the door open to reveal a mostly empty storage closet. The only thing in the room was Simon's body, thrown carelessly into a corner.

He let the pipe fall from his hand as he crossed the room to inspect that it really was Simon. But no amount of hoping would change the facts. Simon's brown eyes stared lifelessly up at him.

With a heavy sigh, Jace stretched Simon out on his back and closed the vampire's eyes. His body was still limp, rigor mortis hadn't set in yet. Jace reached to pull Simon's collar up over the awful slit in his throat and that's when he noticed it.

The wound was still bleeding. The blood on the floor was half dried but Simon's wounds were still bleeding long after he shouldn't've had any blood left. Then Jace pulled his witchlight out of his pocket and studied Simon closer. There was a tiny movement in the vampire's neck, like an impossibly slow pulse.

It was a pulse, Jace realized. But that didn't make any sense. Vampires' hearts didn't beat. But Simon's did, very slowly.

Simon's eyes fluttered open and his lips drew back from his teeth in a snarl, revealing his unsheathed fangs. There was no doubt about it; Simon was a vampire but his heart still beat and, judging by the bleeding, his body was able to produce blood. Jace watched in fascination as his wounds slowly started to heal. Left on his own, Simon would fully recover in time.

Jace decided to speed up the process. Taking the end of the pipe, he tore a gash in his own wrist and held it up to Simon's mouth.

"You can have a pint," he told the vampire and winced as he felt Simon's fangs sink into his skin.

Perhaps a pint and a half later, Simon was shakily wiping Jace's blood off his face.

"I drank your blood," Simon pointed out in amazement. "You let me."

Jace didn't respond, just focused on drawing a healing rune on his arm. "You know that a vampire's heart isn't supposed to beat anymore, right?"

Simon put his head in his hands. "I don't know. I haven't mentioned it to anyone."

"You should probably keep it that way. Can you stand?"

He scrambled to his feet.

"Good," Jace said, grabbing his makeshift weapon. "Now we have to find Jaci and Clary."