I don't think I've really ever written a Mortal Instrument fanfiction (besides half finished ideas in note books).

But I've recently made an accounted on that cursed website known as Tumblr. I have no idea what I'm doing, but I made the mistake of looking up James Carstairs. And thus, this story idea came to mind. (By the way, you should follow me! My username is SurpremeMasterOverlordKhurro )

Before I start, here's some background:

This is about a year after City of Heavenly Fire.

By now, everyone knows that Zacariah is actually James Carstairs.

I'm a horrible person and my goal in most of my stories is to make people cry so know that you've been warned.

This first chapter will probably suck, but I promise the next ones will be better. This first one is just kind of an introduction to set the rest into action.

I do not own the series or the characters.

New York, A few blocks away from the Institute

Jem had been feeling as though he was missing something for a while now. Something other than Will. He was bored being a normal mortal. He wanted to be a shadowhunter again, to once again serve the Angel . He had thought that after losing Will, he wouldn't want to be an active shadowhunter ever again. Jem missed Will more than anything, missed it so much it hurt to even think about him. He didn't think would ever get used to being a shadowhunter without his best friend beside. And yet, after spending about a year watching over Emma Carstairs, he found he once again longed to feel a blade in his hand and experience the thrill of a demon hunt. He figured he would give a try, to see if maybe there was a chance he could become an active shadowhunter once more. But he never told Tess. So when Tessa had been called away for some job the Iron Sisters needed help with, and had dropped Jem off in the New York Institute at his request (claiming he wished to spend a little more time watching Herondales and Lightwoods), he decided to join them on a hunt.

"You're going hunting with a stick?" Jace rose an eyebrow when he spotted Jem's old dragon-headed cane. It had been saved over the generations, and still worked like it always had.

"It's a staff." Jem corrected automatically, remembering a similar conversation with another Herondale. "A very old one at that."

"And old stick isn't going to help you much." Alec came up beside Jace, looking curiously at the dragon carving.

Jem lifted the staff and pressed a button, and the knife sprang out, shining in the pale light that lit the hallway. "An older violin sounds much better than a brand new one. And an older weapon is much more comfortable and broken in than a new one."

The other boys quieted down after that. Now, they were just waiting for Simon, who was the newest and only here for a week on a break from the Shadow Hunter Academy. Just before he had turned 18, him and Clary had become parabatai. After a year at the Academy, he was still not the best at drawing runes, and went very slow so he wouldn't mess up.

Jem looked over the group. Jace, who was so much like Will that he couldn't tell if the two Herondales would've been best friends or worse enemies; Alec, who was shy and timid unlike his ancestors, but looked so much like Will that it always came as a shock to him; Isabelle, who was so unlike Jessimine in every possible way; Clary, who's hair was as red as Henry's had been; Simon, who was, well, Simon. There really wasn't any other way to put it. Maybe he was similar to Sophie? No, not Sophie. Who did Simon remind him of?

He dropped the thought when they were finally ready to go. The night air was colder then London had been, and dryer. Not nearly as much rain, but the air still had that city-smell to it. The buildings were taller, younger, and it was much, much busier.

"So, you knew Magnus?" Alec asked to keep an awkward silence from starting.

"Yes. I knew almost all of your ancestors." He said, gesturing to the rest of the group.

"Were my ancestors as handsome as I was?" Jace asked, half joking.

"Depended on the day. But you can count on them being as stubborn and thickheaded."

"I'm not thickheaded!"

"Yes you are." Pretty much everyone said.

Jace just grumbled a little.

"You knew a Fairchild?" Clary asked.

"Henry Fairchild." Jem couldn't help but smile a little. "Invented the portal with help from Magnus. He was an interesting character, to say the least."

He never got to explain anymore, because just then, they were attacked.

"You should be dead!"

Jem froze when he heard that voice. He had been told the demon had been killed a long time ago. "Yanluo."

Someone bumped into him, and snapped him out of his trance. The disbelief was soon replaced with anger. This was the demon that made Jem an orphan, the reason he had been so dependent on that drug, the demon that eventually was the reason Jem had been unable to grow old with Will.

"You should be dead too." He growled, throwing a dagger at the Greater Demon. While it hit him, it didn't kill him. It just made him mad. The demon lunged, and Jem dodged, but then he realized Yanluo wasn't alone. Rogue werewolves were with him. The werewolves were keeping the other shadowhunters busy, while Yanluo was focused on Jem. The fight was a blur for pretty much everyone. While they had been out on a hunt, they had let themselves be distracted. A stupid mistake and they all should've known better. But Jace saw how the battle ended. At some point, Yanluo had lunged for Alec. Jace didn't have time to yell out a warning, but before the Great Demon could get to Alec, Jem had jumped in, stabbing the cane deep into Yanluo's head, but being smacked into a brick wall at the same time. It was hard to explain. The Greater Demons hissed as it died, ichor dripping down its face, around the dragon-headed cane.

The werewolves took off once they realized Yanluo was dead. Alec was the first one by Jem's side, having been the closest to the wall. The ex-silent brother was unconscious, bleeding badly from his head and from deep gashes in his side. Alec frantically felt for a pulse, and let out a breath he hadn't realized he'd been holding when he felt the faint thump of his heartbeat. Clary and Jace got on their knees next to him. Her stele already out, Clary quickly drew a rune on Jem's side and his head to slow the bleeding.

"Make a portal to the Institute." Jace told her, taking charge as he often did. "Alec, call Magnus. Isabelle, call Maryse and have her summon the silent brothers."

"What about me?" Simon asked.

"Help me carry him." Jace grabbed the top half of Jem, while Simon grabbed his legs. Clary already had a portal open, and they all stepped through, into the infirmary. The next few tense minutes went by in a blur, and the young shadowhunters waited in the hallway for updates.

Again, I'm sorry about how crappy and rushed that was. I just needed something to set the rest into motion. You'll see!