This is my first attempt at a crossover fic, so don't shoot me if it's bad!

This is set two months after Mortal Coil and six months after City of Glass (just pretend that the City of Glass events happened in 2010 not 2007).

Disclaimer- As much as I'd like to own the series I don't because Mortal Instruments belong to Cassandra Clare and Skulduggery Pleasant belongs to Derek Landy!

The airport was packed and Clary could barely hear herself think for all the noise. People kept barging into her -accidentally of course- and it was hard to navigate herself to the front desk. It was the first week of the summer holidays and everyone was itching to leave the state and fly somewhere warm for a holiday. Clary wasn't going anywhere warm though; she was going to rainy Ireland with Jace, Isabelle, Magnus, Alec and Simon.

"I still don't see why we couldn't just portal over," Jace groaned.

"Ssh!" Alec said, putting his fingers to his lips "You don't want any mundies hearing about portals do you?"

"Portalling would have been so much easier," Jace said, ignoring Alec's comment. "Instead we have to wait in this mangy, mundie airport for two hours and if we don't get crushed first then our eardrums will burst from all this noise!"

"You think you've got it bad? Try having vampire hearing! I can hear stuff coming from the planes outside!" Simon joked.

"Ssh!" Jace said, mimicking Alec in a girly voice that sounded nothing like Alec's voice. "You don't want any mundie's hearing about vampires do you?" Both Simon and Alec shot Jace an evil glare, though nothing that could blow Isabelle's death stares out of the water.

"Can you all just be quiet for one minute?" Isabelle groaned. "You're all so immature!"

In a bid to change the subject Clary pointed towards the desk and led them there to get their luggage weighed. Knowing Isabelle, her hand luggage would be double the amount it normally should be because of all the random junk in it that she wouldn't need. Fair enough putting in some magazines, a phone, an iPod, a purse or maybe even some makeup, but Isabelle had her hair straighteners, her hairbrush, dozens of necklaces and even a change of shoes! Why Isabelle would need straighteners for a plane journey Clary would never know. However, while Isabelle was known for her makeup-and-hair obsession, Magnus was even worse with his glitter-and-guyliner obsession, so she dreaded to think what was in his bag. There wasn't a limit on hand luggage, but there was on normal luggage and judging on how much was just in Isabelle's handbag, there was no way it would be within the 23 kilo limit.

"Hello," grinned the girl behind the counter who looked like she was in her late twenties. She had dyed blonde hair. Clary could tell it was dyed because nobody had hair that blonde with eyebrows that dark, not that you could tell because her eyebrows had been plucked so much they looked like a very thin line drawn on with pencil. "Where are you going?"

"Dublin, Ireland." Alec said in a flat tone, without any hint of emotion in his voice.

"Ooh, I've never been to Ireland. Is it for pleasure or business?"

"Pleasure, we're visiting some relatives." Alec lied. They weren't actually visiting any relatives, they didn't even have any relatives in Ireland, but instead were doing Clave business. Although strictly speaking, it wasn't technically Clave business as they hadn't been called there but Magnus had some warlock friends in Ireland and they'd told him that they were in trouble. Naturally, Magnus agreed to help them and got his boyfriend and friends to come with him. Magnus hadn't actually told them what the danger was, but he said it was Shadowhunter related so it could be classed as Clave business.

"How lovely! Now would you put your luggage here please, we need to check how much it weighs."

Alec was the first to weigh his luggage. His plain black suitcase was 10 kilos less than the limit. Clary wasn't surprised really, Alec didn't care much for clothes and shoes so he only packed the necessaries. Jace was next, his camouflage suitcase was almost over the limit but it was 0.1 short so he didn't have to pay extra. Clary wouldn't what he had in there. Probably a few dozen mirrors so he could stare at his own reflection for entertainment. Simon's badge-adorned blue suitcase weighed the same as Jace, and surprisingly Isabelle's bright pink suitcase didn't tip the scales either. Neither did Magnus' rainbow suitcase, which was probably the biggest shock to her. But when it was Clary's turn, her flowery suitcase -the same one she'd had since she was five- went over the limit. She gasped; how come her suitcase was too heavy but Isabelle and Magnus' were fine? She'd tried to hard to pack light and hers wasn't filled with junk.

"Ooh, it's 2 kilos over the limit. You're gonna have to pay the fine I'm afraid!" said the girl, in a slightly forced perky voice. Groaning, Clary fished a few dollars from her purse and handed them to the girl behind the counter. Had Isabelle snuck a few of her things into Clary's suitcase? Yes, that seemed to be the likely explanation.

When they were out of sight, Clary decided to confront her. "Isabelle, how come my luggage was over the limit when everybody else's was fine?"

"Oh Clary," Isabelle laughed. "We used a lightening Rune!"

Clary was astounded. There was a Rune to make things lighter and she hadn't used it?

"How come nobody told me?"

"Well I don't know, but seeing as your angelic powers allow you to create new Runes we assumed you knew all about them!" Jace mocked. Clary scowled.

"Well, are flight isn't for another two hours, what shall we do now?" Simon asked the group.

"I have an idea…" Magnus said, with a seductive look in his cat eyes.

Fletcher hated the rain. Usually when it was raining he'd simply teleport himself to Australia, or somewhere else where it was warm, but now that he was part of a team he couldn't exactly just leave randomly all the time. Of course, that didn't stop him from teleporting; he often took Valkyrie for trips around the world, but they could never stay too long as Skulduggery might get annoyed. Although it seemed like Skulduggery was annoyed at Fletcher no matter what he did. He figured that he was just jealous of his awesome hair.

Drumming his fingers on the wooden table, something which always wound Skulduggery up, Fletcher waited impatiently for his girlfriend to arrive. Fletcher was waiting at Skulduggery Pleasant's house along with Ghastly Bespoke for Valkyrie Cain to arrive. Skulduggery said they were expecting guests from America this evening, a mage, a vampire and four people called "Shadowhunters." Fletcher was unsure what that term meant. Were they people who hunt shadows? That didn't seem very exciting, especially because shadows don't really cause any harm. Perhaps it was just an American term for Necromancers, although that was highly unlikely seeing as Necromancers wouldn't want to hunt shadows but embrace them. They loved darkness and death. His girlfriend was studying Necromancy, something which Fletcher and Skulduggery didn't really approve of- one of the few things they had in common.

"Fletcher either find something else to do, preferably something to fill that empty head of yours with some intelligence or just stop tapping your fingers." Skulduggery snapped. He didn't have his façade on so he was his usual skeleton self.

"Fine," Fletcher said, running his fingers through his blonde hair. Strutting towards the large mirror on the wall, Fletcher began to tease his hair into the usual spiked style that Skulduggery usually called the hedgehog look. He was just jealous that Fletcher had gorgeous blonde hair when he didn't have any. Fletcher looked at his reflection and smiled. He was gorgeous and wasn't afraid to admit it.

"What time are our guests supposed to arrive?" Ghastly asked, not looking up from his book. He was studying a book about remnants, presumably to see if there was a cure for Tanith who unfortunately had a remnant bound to her two months back. Once a remnant had been inside of you for four days then it was permanently bound to you, but poor Ghastly was so heartbroken he'd never stopped searching for a cure, though he never showed his desperation.

"She should be here now, she just had to collect a few things from home." Skulduggery replied, peering out the window. Fletcher wondered how a normal passer by would react if they saw a skull head poking through the curtains.

"What time are our American friends arriving?"

"They should be here in approximately an hour and a half, depending on traffic."

"Traffic? What in the air?" Fletcher joked.

"Oh yes, the sky can get very busy sometimes with all the witches on broomsticks and flying monkeys and such." Skulduggery said sarcastically. Fletcher ignored that comment and carried on staring at his reflection. He looked good, as always.

At that moment, the beautiful Valkyrie Cain entered the room. She was wearing the protective clothes that Ghastly made her, a long black coat with sleeves the colour of dried blood, black trousers and tall black boots. Her dark hair was loose around her shoulders and a subtle hint of eyeliner and mascara painted around her brown eyes. Fletcher's mouth hung open. How lucky was he to have a girlfriend who could look so hot without even trying? He hated to admit it but she looked almost as good as he did.

"Shut your mouth Fletcher or you'll catch flies," the brunette smirked. "Have our guests not arrived yet?"

"Judging by the fact that the house is not filled with endless high pitched banter of 'hey' and 'girlfriend' I'd say no." Skulduggery said flatly. Fletcher could tell that he wasn't looking forward to housing American guests, even if one of them was his friend. He felt sorry for the people coming to stay, Skulduggery wasn't exactly the most pleasant person to be around despite his last name. He wondered how they'd all fit in his house, it wasn't exactly the biggest place in town. But then again, where else could they stay? Valkyrie lived with her parents who didn't know about magic so they couldn't stay there. Ghastly's house was smaller than Skulduggery's and he doubted he would trust new people in his shop as he'd fear they might steal or break something. Fletcher didn't really have a home; he'd just teleport to random hotels and stay there without having to pay. They couldn't stay with Tanith because now that she had a remnant inside of her goodness knows what could happen, the temporary sanctuary was off limits and they definitely couldn't stay in an ice cream van with the zombies Scapegrace and Thrasher. Maybe they could stay with Ravel, but he wasn't sure if he even knew about the American guests. The only other place he could think of would be the Hiberian Cinema, but that didn't seem like a good idea now what Kenspeckle was gone.

"Hang on, I'm getting a text." Valkyrie said, feeling around in her coat pocket for her phone. "It's from Magnus, they're here. They've landed in Dublin and they're at the airport now."

So how did you find it? It's my first crossover so be nice :D Review and you'll get the pride of knowing you reviewed!