A/N: A highly uninventive title, I know... As prompted by tumblr folks, here we are! Feel free to point out mistakes, I'm a bit unwell so it might not be as good as usual!  

What the literal hell?

Magnus finds himself asking that very question as he feels something - or rather, a specific someone - break through his wards as if they don't exist.

Groaning, he pulls his lips away from his shadowhunter's and blinks, his golden eyes vanishing, replaced by a brown deeper than the layers of his personality. Alec, still sort of breathless, only cocks his head in confusion.

"Stay behind me, darling," Magnus murmurs as he threads his fingers in between Alec's, leading the two of them to the living room.

Alec has regained a steady breathing rate by the time they enter the room but the breath is taken from him as soon as he sees the foreign figure in their home, standing right in front of the bookshelf they'd only just rebuilt after an angry client had thrown venom at it.

"Magnus!" the man who's not really a man exclaims, smiling widely.

Magnus, despite being as tense as a rubber band about to snap, forces himself to stay as still as possible So Alec doesn't freak out on him.

"Asmodeus." Magnus' voice is hard, monotone.

He can hear Alec echo the name behind him twice, once to register it and another to truly comprehend what that means. Magnus swallows his annoyance and raises an eyebrow at Asmodeus. "Don't you have an Edom to trouble?"

"Don't you have any manners to use?" Asmodeus fires back. Literally fires back, since the question is accompanied by a sphere of flame thrown at them. Magnus just rolls his eyes and reaches out to grab it, killing it with blue sparks of his own.

"This wasn't exactly how I'd expected this day to go..." Alec mutters.

"So you're the one Magnus has been hiding from me, huh?" Asmodeus grins, his gaze moving up and down Alec's frame.

Magnus tenses, his whole body on high alert and his magic lurking just behind his skin, waiting to defend his Shadowhunter. He practically holds his breath as Asmodeus steps towards them, choosing to circle them like a pack of wolves waiting to pounce. He can feel Alec shift closer to him as the scent of fire and blood and metal becomes stronger and stronger.

"Interesting choice," Asmodeus says eventually, halting to a stop in front of Alec. Alec, slightly confused, tentatively smiles and squeezes Magnus' hand to say he's ready in case they need to attack.

"Noted." Magnus' voice is blank, practically lifeless. He itches to turn and shield Alec but he knows there's really no point; he's almost helpless and he can't stand it.

"Tell me, Shadowhunter," Asmodeus orders, "have you seen his warlock mark?"

Alec clears his throat before nodding. "His eyes? Of course, they're beautiful."

"Are they now?"

"Yes." Alec nods once more, not losing eye contact with the greater demon. "They're the most beautiful thing I've ever seen, aside from the rest of Magnus, of course."

"Of course..." Asmodeus echoes, walking around to face Magnus. "Alright, alright, put that magic away already!"

"Forgive me for being a little on edge when a Prince of Hell appears inside my wards."

"When will you learn? Your wards are practically my wards and I don't care much for wards."

Alec chuckles. "Now I see where you get it, Magnus."

"Oh, hush, Alexander..." Magnus wants to sound reprimanding but he can't hide the amused smile on his face either.

"Alexander..." Asmodeus repeats the name as if it were a precious secret. "Magnus and Alexander..."

"I'd certainly hope so," Magnus replies, now utterly bewildered.

"Fancy visiting Edom, Alexander?"

And, just like that, Magnus is on edge again, a small frown on his face as he bites his lower lip. Asmodeus notices his tense muscles immediately and laughs. "You really think I'm here to drag your boyfriend away?"

"No offence, Asmodeus... Uh, your majesty... But you do look like you want to burn us to the ground..." Alec regrets opening his mouth immediately after saying that but Magnus chuckles behind him and finally steps sideways so the two of them are in line with each other.

"The only burning I want to do is to my own eyes after seeing your sickeningly unfaltering hand-holding."

Magnus and Alec share a sideways look with one another before simultaneously turning to Asmodeus and raising their eyebrows. Ignoring the doorbell that sounds like it's coming from a mile away, the two of them wait for a reply or an explanation or anything that can satiate their puzzled curiosity. It's not every day that a greater demon manages to compliment you with an insult.

"I have a warning for your Shadowhunter," Asmodeus admits to Magnus after waiting for the doorbell to stop chiming. Even though Alec and Magnus both stiffen at the words, Asmodeus pretends to - or really does - ignore them and continues, "So, Lightwood, If you hurt Magnus in any way at all, I will burn you and everyone you love into- oh, what's that word- smithereens."

Alec blinks. "If I ever intentionally hurt Magnus, I'll burn myself before you get the chance."

Having recovered from his initial shock, Magnus coughs. "Can we stop discussing the annihilation of my boyfriend, please?"

Despite the serious threat to Alec's life, Magnus can't help feeling both touched and disorientated. He's not used to being the recipient of protective warnings, he's usually the one dealing the threats. And he's definitely not used to Asmodeus, of all people - or rather, of all demons - showing a caring side. Of course, this unprecedented display of affection is immediately broken when Asmodeus says,

"I wouldn't want anyone else to take away the fun of hurting you, Magnus, would I?"

"Duck!" Alec yells, pulling Magnus towards himself even as he says it. A moment later, Magnus' knees hit the floor along with Alec's, both of them stifling their groans and turning to watch the odd fireball that'd appeared out of nowhere hit the bookshelf, causing everything to topple on the carpet and shower the area with sawdust and ripped papers.

"Why does everyone target the bookshelf?" Alec mutters, his arms still wrapped around Magnus as a shield.

"We're going to have to move that shelf, darling."

Asmodeus coughs to get their attention. "Don't mind him, he was just reminding me I have another visit to make. Have fun with the interior decorating and... Don't make me have to return." A moment later, he adds, "That shelf had it coming anyway, it's full of appalling novels..."

Before Magnus can jump up and protest, Asmodeus has vanished as suddenly as he'd arrived, taking the scent of Edom with him and leaving behind two very confused individuals who both start to fix the damage inflicted on the apartment.

"What would he know about the rankings of novels?" Alec asks, his voice laced with both irritation and relief, as he picks up one of the few unscathed books.

A smile on his face and sparks around his hands, Magnus shakes his head. "Don't concern yourself with my father's taste in literature."

"Magnus." Alec freezes.

"Yes?"

"Did I just meet the in-laws?"

"Well, technically, you only met one of them."

Alec's eyes widen comically, his face draining of half its colour. "That was a terrible first impression, oh- by the angel, he's going to come back and-"

"Alexander." Magnus takes Alec's hands in his and smiles. "You did magnificently."

"Are you sure?"

"Did the Ruler of Edom just destroy our bookshelf?"

Instead of answering the question, Alec laughs. He isn't even sure why he's laughing but figures it's a reasonable response to being threatened by the prince of Hell who just so happens to also be the father of your boyfriend. It's fine, though, because Magnus is laughing with him and the two of them can choose to temporarily forget the perplexing encounter until they're free of shock and adrenaline, focusing on trying to restore the unfortunate shelf instead.

I can't wait to watch the next episode, the first one basically killed me. Have a nice day <3