I am surprised at how few crossovers of The Mortal Instruments and Supernatural there are. The stories are so similar to me. I was curious as to see if it was a lack of interest that was the reason behind the poor numbers, or whatever else is the reason. Anyway, tell me what you think and enjoy.

Chapter 1: Djinn Attacked

"This was not a good idea," Sam muttered to himself for what felt like the hundredth time since they had entered the long abandoned warehouse on the outskirts of Brooklyn, New York.

However, Dean had seemed convinced that barging into the possible hideout of three djinn with no plan or backup seemed like a brilliant idea with just their bronze knives and lamb's blood. But Dean had been acting reckless and a little stupid ever since they picked up on the possible hunt.

Sam knew exactly why Dean had been so quick to jump on the job after a couple of bodies had shown up seemingly surgically drained of all their blood. Castiel was still missing - for all they knew dead. Not that either brother would ever admit it out loud, but it was on both's minds. And when Dean didn't want to deal with problems like this, he threw himself into a hunt safety or caution be damned.

A loud creak was heard somewhere further in the old building and Sam and Dean froze. "Hear that?" Dean asked quietly.

"Yep," Sam replied, lifting his knife in a more ready position.

The creaking noise came again, but instead of stopping the brothers continued quickly and quietly making their way towards where the noise was coming from. As they kept going, the creaking became louder and other sounds were added to it. Sam became certain that the two of them were not the only creatures in the building.

They came upon a large, metal door that was cracked open allowing just a sliver of the next room to be seen. The two brothers stopped, listening to see if they could tell whether or not the djinns were having a night in. They heard voices speaking in whispers, but not those they were expecting.

"What could be doing this?" asked a high pitched female voice, who seemed to be very confused.

"No idea," responded British accented male.

"I'd say vampires," replied another girl, also with a British accent, "but then again I've never seen vampires drain their victims with medical equipment."

The hunters gave each other confused looks before silently moving to see what they could from the cracked door.

What they found surprised Sam. He could make out the silhouettes of three people. The light coming from brightly lit streets seeping in from the high windows showed them to

be young - the three of them couldn't be older than 20 or so. There were two girls to match with the two female voices they had heard. One was short and almost pixyish, the other tall and willowy. The third teenager - and only male was tall as well; he was examining the two dead, bloodless bodies lying on the ground. Sam could also see the IVs set up which still had traces of blood in the hanging bags.

Sam watched curious as to what three teenagers were doing in the middle of the night trying to determine what had killed the two people. What had really thrown him for a loop was the suggestion of vampires as a completely plausible explanation. For a second he had thought it was Krissy, Aiden, and Josephine on a hunt. But he quickly dismissed the thought after remembering the two British accents he had heard and catching a glimpse of the tattoos that covered all three's bodies. Besides Krissy, Aiden, and Josephine should have been able to tell it wasn't vampires but djinns that were the killers.

"Kid hunters?" Dean whispered up to Sam, staring intently at the group before him.

"Maybe." Sam responded, planning to say more, but stopping when he heard the boy speak again.

"Well, we should probably call Maryse and get the Clave on it. I still don't know what it is, but this whole place reeks of the supernatural."

"Supernatural and creepiness," the taller girl agreed.

"Just call her Isabelle," the boy sighed, running his hands through his hair.

"Give me a second, Jace," she retorted as she whipped out what Sam assumed was a phone and pushed a few buttons before holding it up to her ear.

"Yeah, Mum?" the girl asked. "Jace, Clary and I went over to Simon's, but on the way back we heard screaming from inside this old warehouse and went in to investigate. By the time we found who we think were the screamers they were dead."

The tall girl - Isabelle's - mother seemed to respond because Isabelle didn't speak for a moment.

"We think it was supernatural. I mean the two bodies are drained of blood. But the weird part is it looks like it was medically removed because there are IV drips and blood on the floor."

The mother seemingly responded again.

"Vampire does seem like the most likely answer, but what kind of vampire goes all doctor on their humans?"

"That's because we're not vampires," came a cool clear female voice from the shadows behind the teenagers.

"Crap," Dean muttered.

"You can say that again," Sam agreed. "Do we go in now?"

"No," Dean instructed. "Let's let it play out a little bit longer. See were it goes."

Sam said nothing and went back to observing a woman walk forward with the fluorescent blue markings of a djinn growing from her fingertips all the way up her arms.

Isabelle, Clary, and Jace and whipped around to watch her approach - Isabelle dropping the phone.

"What do you mean we?" demanded Jace, glaring at the woman.

"I mean my brothers and I," she smirked. Two more djinns came to stand beside her.

"What are you then?" the shorter girl - Clary - asked a little shakily.

The female djinn kept smirking turning her head to the shortest of the three.

"Why I thought you Shadowhunters knew everything. Or are you telling me you all aren't the all knowing gods you think yourselves to be?"

"At least we aren't killers," spat back he boy.

"That's up for debate. It depends on the point of view," one of the male djinn said darkly.

"Well what's not up for debate is the fact that you three killed these two innocent people," piped up Isabelle.

"Five," the female djinn corrected, picking at her cuticles.

"What?" Jace snapped.

"Five people. These two plus you three makes five. Though, I suppose the innocence of the kills will be in question at that point." The female djinn looked positively gleeful at the idea of killing these Shadowhunters, so much so it took Sam a little aback.

The boy raised what appeared to be a long dagger before calling out Samandriel, at which point it began to elongated and glow. A golden whip was being uncoiled by Isabelle and similar weapons to Jace's bright sword were being gripped by Clary.

"Idiot Shadowhunters. Your precious seraph blades and runed weapons won't do a thing to us. We are not demons."

"Now?" Sam questioned his older brother, anxious to stop the djinn before this got out of hand.

"Now," Dean agreed as he reached to yank the door back before the two entered blood- soaked bronze blades in hand.

The Shadowhunters and djinn turned at the sound of the metal door straining against the hinges as it was swung back revealing the two brothers.

"Seraph blades and runed weapons might be useless against djinn but I have a funny feeling bronze daggers dipped in lamb's blood might be a little more effective against you three," Dean grinned, waving the knife at them.

While Jace, Isabelle, and Clary looked confused - the three djinns looked angry and afraid.

"You'd have to hit me with it first," the female djinn snarled, her hands beginning to glow blue along with her eyes as she crouched in a fighting stance, her brothers following suit.

At that point Sam let his years of hunting and instinct take over and raised the knife in front of his body. Before he could even blink one of the male djinn was on top of his snarling and trying to lay his glowing blue hands anywhere he could reach on Sam. The younger Winchester fought back, jabbing and swinging the knife along with punching and kicking at the supernatural creature before him.

It wasn't long before Sam saw an opportunity to end the fight early when the djinn tried to grab his free hand, bending forward slightly and leaving his back exposed. Sam jabbed the knife into its back watching as the blue that seemed to course through the djinn's body flicker and die along with the monster.

Hearing a scream, the hunter yanked the the knife out of the now dead body and turned around to see the female djinn attacking the Shadowhunters. Sam ran over, kicking the female djinn's legs out from under her. Unlike one of her brothers, though, she proved to be a more experienced fighter, punching Sam in the gut and managing to knock him off balance giving her enough time to get back up on her feet.

This particular djinn was good enough to get the upper hand on Sam and bring him to the floor. She perched on top of Sam and smiled darkly, bringing her glowing hand up to his face.

"Shame to kill such pretty packaging," she practically cooed - her hand hovering over Sam's face. She leaned forward, her smile growing wider before keeling over to reveal

Clary frowning at the knocked out djinn - still holding out the butt of one of those glowing swords.

Before the impaired djinn could recuperate swung to the side, jamming the blood crusted dagger into the djinn's heart - the blue fading out like her brother's.

"Thanks," Sam nodded to Clary who gave him a small smile. "Anytime."

"Are those trials still taking it out on you or are you just that out of practice you need a pint sized girl to knock the djinn out before you kill it?" Dean snickered standing behind his own kill.

"I killed two to your one, Jerk," Sam groaned, standing up while clutching his side. "Bitch," Dean replied almost absentmindedly while taking in the damage.

"Who are you two and what were you doing here?" Isabelle cut in, smoothing down her slightly out of place hair.

"Us?" Dean asked, pointing to himself and then to Sam.

"No, the other two guys who marched in here and killed the - the whatever they were," Jace quipped.

"Watch it, Smartass," Dean told him. "I'm Dean that over there is my little brother Sam. Your turn."

"That doesn't explain why you're here in the middle of the night killing people," Isabelle argued.

"We could ask you three the same thing," Sam pointed out.

Both Isabelle and Jace looked like they were about to argue when Clary beat them both to it.

"I'm Clary, that's Jace and Isabelle. We're what's called Shadowhunters - a sort of supernatural police force, I guess. We were coming home from a friend's house when we heard screaming and came to see what was happening. What about you?"

Neither Jace or Isabelle looked happy at Clary telling the complete stranger what little she had, but she ignored them.

Sam smiled at the girl. "We're really just two guys who know a thing or two about the supernatural and try to put a stop to it when it hurts innocent people. We heard about the missing persons and the bodies that have been showing up"

While Sam was giving the vaguest answer he could, knowing his older brother wouldn't be happy with anything less, Isabelle had picked up the dropped cell phone and dialed her mother's number again.

"Mom?" Isabelle talked into the phone. "Yeah, sorry about that. We were sort of ambushed. Yeah, everybody's fine. Uh . . ." Isabelle looked around the room until her eyes landed on Sam. "Just a second, Mum." She held the phone away from her mouth and asked, "What exactly was it that attacked us?"

"Djinn," Dean responded offhandedly.

"Djinn don't glow blue and drink human blood," Jace countered.

"This kind does," was Dean's only offer of an explanation. Sam rolled his eyes at his brother.

Isabelle talked to her mother again. "Apparently it was a mutant strain of djinn." The mother spoke for a few moments before Isabelle talked again. "Two mundies named Sam and Dean. Yeah, there the ones that actually killed the three djinn. I guess they just have the sight. Uh huh. Yeah. Okay. No I don't know that. Well, I could ask."

Isabelle put the phone down a second time who looked between the brothers. "My mum wants to ask you over for dinner. She wants to talk."

"Talk where," Sam asked cautiously.

"At the New York Institute. My family runs it," Isabelle explained. "She wants to meet you and talk."

Sam and Dean exchanged a quick look - neither wanting to really go, feeling like it was a bad idea. But at the same time, danger had never really phased the Winchesters and they were both curious about who these Shadowhunter people were.

Dean nodded gruffly before turning to his brother, looking for confirmation in their dinner plans.

"Lead to way," Sam said.