A/N Hi there! So, this is obviously a quadruple-crossover. Superwhovengerlock, as I call it, though I've also seen 'Superwhoavengelock' floating around. I've already written this whole thing out, and will be posting one chapter (out of fifteen) each week. The first bit might be a bit difficult to understand, so I probably ought to explain: the idea here is that the Master, Moriarty, and Loki all had an alliance before they each got killed off/defeated, where the three of them basically helped each other out with their evil plans and whatnot. Ahem. The setting for this story is as follows: post-movie for the Avengers, post-Reichenbach for Sherlock, mid S5/S6 hiatus for Supernatural (when Dean's living with Lisa and Ben), and post-season 6 for Doctor Who. And I think that's about it. Oh, wait, one more thing- the image used as a 'cover' for this story is in no way mine, and will be taken down if requested. Enjoy, please review!

Rated T for language and violence in later chapters

Disclaimer I don't own the Avengers/Doctor Who/Supernatural/Sherlock or any associated characters, events, etc.

To the right, to the left, we will fight till the death
To the edge of the earth, it's a brave new world
From the last to the first, to the right, to the left
We will fight to the death, to the edge of the earth
It's a brave new world, it's a brave new world

~ "This Is War," 30 Seconds to Mars

CHAPTER I. Shadows

Asgardian prisons never had much of a reputation in the first place, positive or negative, but if they did, it should have been for their stench. After three days stuck in his own small, damp cell, Loki was positive of this. It was the most utterly repulsive of odors—mildew soaked in cow urine, he decided, twisting his face into a new version of the grimace that had been cast over it ever since they removed the ridiculous muzzle placed on him by those absurd Avengers.

Avengers. Just the name sent a ripple of hatred through him, and his teeth clenched with disgust as his hand ran along the stone wall, withdrawing as soon as icy moisture began to collect on it. There was nothing that they were avenging at all. Just protecting their precious Earth, never even allowing a chance of what he offered. He'd made it clear enough, hadn't he? You crave subjugation. If they'd been strong enough to simply see past the veil of individuality that society had blinded them with, realize that there was no need to fight, that peace was a perfectly acceptable option…

Because he had nothing against peace, nothing at all. Yes, he'd had an army, but the literal first bullets had been fired by the humans, by Fury's SHIELD, practically the very instant that the Tesseract allowed him entrance into their world.

Never being given a chance… oh, that was a scenario that Loki was all too familiar with.

He suddenly snapped his head to the side and curled his hands into tight, straining fists, his teeth bared and rendering his emaciated, pale face little more than a grimacing skull, frosty eyes shining out of dark sockets. Confinement had reduced the god, formerly grand to behold, to a bony, greasy-haired mess, and his mind was contorted to match, twisted past the breaking point of its former shaky sanity. What he needed now, more than ever, was revenge.

Revenge on the Avengers. The phonetically redundant sentence couldn't have sounded sweeter. His lips twitched, framing the words, as he sunk into the corner of his cell, arms cinched tight around his legs and spine shaking.

Revenge.

Revenge.

Revenge…

The two Asgardians positioned outside of the defeated Frost Giant's small room, though neither would mention it to the other, were rather chilled by the undeniably mad motions of the creature they were meant to be guarding. They both knew Loki's story, his many crimes as well as his punishment—and that punishment, it was only a day away now, only one more day of them having to assume these tense positions outside of his cell, watching him pace like a caged beast, eyes growing wilder by the hour.

It was death, naturally, that had been ruled as fair recompense. Loki should have died long ago, and now his time had finally come. Come morning, he'd be bound at the mouth and wrists, taken before Odin and Thor and executed formerly. The latter of two made it no secret to the rest of Asgard that he was vehemently opposed to such a thing, but the verdict was absolute. Nothing about Loki's position was worthy of survival.

The guards had no idea that they'd never live to see that dawn.

They died simultaneously, given a single moment of shock as their staffs were suddenly ripped from their hands, swung around and slid between their ribs, the sharp edge tearing flesh effortlessly and ripping through heart, lungs, reaping their lives as cleanly as any scythe. Neither had time to so much as gasp before sinking to the ground, entirely motionless.

The laugh that sounded was low but young, and, as shown moments later, belonged to a tall, dark-haired, and apparently human man, who seemed to blur into existence as he lifted a long necklace over his head. "Perception filter, you say?" he chuckled, his eyes flashing as the action was copied beside him, revealing a slightly older-looking blonde, also of humanoid appearance. "Entertainingly effective, I must say."

The blonde nodded. His lips curved into a slight grin as well, but it was different, faintly intimidated, almost—it was clear that he held the other in a high light, respect that almost approached worship. "They have proved quite useful in the past." Unlike the other's smooth American purr, his voice was faintly accented in what a human would have recognized as British.

"And the present as well." Hefting his stolen staff, the younger-faced man turned towards the shimmering, silver-tinted wall of what seemed to be pure energy separating them from the hunched, oblivious figure of Loki. "Now, let's not waste time—best to do a clean job, don't you think, grab your friend and get out of here?"

"He's not… my friend," the other corrected delicately.

"Oh? And what would you call him, then?"

"…An associate," he decided after a moment of contemplation, "a rather… unwilling associate. It was all Mr. Moriarty's idea—"

"Moriarty," the brunette repeated softly, tilting his head and raising his eyebrows. "The one who you're relying on me to pull back up for you."

"If it's not too much of a trouble, I did do you a bit of a… favor… even with the majority of time and space energy harnessed, it was rather challenging to pull you out of that… Cage."

"You owed it to me." The words were precise, and carried with them a coldness that clearly didn't go unnoticed by the other, who nodded and lowered his eyes. "However hard you might have found it to contradict my magic with your science, I can promise that blasting you out of that time loop was far from a breeze, itself. Everything that I do now, Master, is entirely out of… the kindness of my heart." His lips pulled away from his teeth in a predatory grin, and his eyes gleamed again, a dark shine that was undoubtedly more than a simple trick of the light. "I'd advise you don't forget that."

"Of course not."

"Excellent." He twirled the staff again, then prodded at the energy field with it, looking delighted as the silver wall parted like a curtain before dissolving into fragments of mist. They were left with nothing between them and Loki, whose head suddenly snapped up, his cold sweat-streaked lips parting in amazement as he sprang to his feet, his orb-like eyes flickering back and forth. His hands were flung out as though seeking purchase in the air, knees bent in what was clearly a defensive stance.

"You aren't of Asgard," he whispered, his voice little more than a hoarse gasp.

"Got that right," the brunette man agreed with a low laugh, his fingers tightening around the staff. Loki's gaze flickered over to the blonde, and his shock turned into glee as an unnatural smile encompassed his dirty features.

"Master."

"Loki," the Master greeted, a certain degree of coolness evident in his voice.

"Oh, but this is fantastic." Loki's posture evened itself out slowly, and he took a shaky step forward. "We were under the impression that you were imprisoned in your war of Time, but here you are now… found a way to escape…?"

The Master's head dipped in agreement, and he gestured towards his companion, who folded his hands over the top of his staff and rested his chin on them, smirking widely.

"This is Lucifer."

"Lucifer," Loki repeated slowly, his voice still scratchy and faint. "The humans' Devil."

"Everyone's Devil," the brunette confirmed with a wink. "Your Master pal needed some help getting out of that Time War, and, lucky for him, I existed even then—space isn't a big deal for us angels, you know, fallen or otherwise... didn't take much of an effort for him to summon me and make the deal. I broke him out of there, he pulled me from the Cage I was imprisoned in. That's when he mentioned his two allies, and I was curious enough to stick around. Also an alien, are you?"

Loki blinked slowly, his teeth glinting in a slight irritated grimace. "I am a god. Far from an alien."

"Well, see, I've met gods, and you're a bit different. I'd say you're just a super-fancy extraterrestrial who happens to be just a bit more powerful than your buddy here."

A snarl escaped Loki's lips, his expression tight with aggression, and a hint of anxiety worked its way into the Master's tone as he spoke up. "There's no need to get upset," he insisted; "we're all here for the same purpose, aren't we?"

Exhaling gradually, Loki's stiff figure relaxed by degrees. Lucifer just grinned wider and glanced over his shoulder. "Not very long," he murmured softly. "Say we get out of here before anyone stumbles upon us?"

The Master gave a terse nod and turned to Loki, muttering out of the corner of his mouth. "We're going to go back—Lucifer intends to help us retrieve Jim."

"Retrieve him?" Loki tilted his head, a cold sort of concern touching his features. "Why would we need the help of someone like this… angel, as he calls himself?"

"Your precious Moriarty is dead," Lucifer retorted bluntly, giving no regard to the abrupt shift in Loki's expression. The Frost Giant's mouth opened slightly, and his wide eyes gleamed with a faint echo of what could be distress.

"Dead?"

"Suicide, as a matter of fact." He sounded practically gleeful. "Shot himself right through the head. Didn't even make the news, despite the… dramatic circumstances…"

"Elaborate," Loki snarled, a new sort of venom gripping his tone. The Master casted him a worried glance, but he seemed oblivious, his stare fixed on Lucifer.

"It was all part of his big game," Lucifer sneered. "Set up a trap for Sherlock Holmes, but ended up with his own neck under the bar. Holmes was killed, as they say, but he needed Moriarty's suicide to prompt it. So it is that you and Mr. Time Lord here find yourselves in need of my assistance."

"…You're Lucifer… Satan. You can bring him back?"

"I can give it my best effort."

Their stare held itself together for a moment, piercing and electric, pale, frozen eyes boring into dark, lazy ones. Loki's face was pulled into a feline hiss, frustration clear in his twitchy, straining muscles. "…Fine," he finally panted, his eyes flickering downwards in what was clear as a forcedly submissive gesture. Tension hummed between the three beings, palpable in the expressions of Loki and the Master, though Lucifer looked absolutely at ease.

"Excellent. Now, let's head back as soon as possible…" He waved his hand in a quick, sharp motion, and the air around his fingertips seemed to swirl, shining a milky white and creating a spiral that soon grew into a windy whirlpool, thick curls of silver and cream blending and twisting together. A low howling noise emanated from it, but neither the god nor the alien reacted to the chilling sound, and the Devil just seemed entertained. "Step right through—first class transportation to planet Earth, with absolutely zero carbon emissions."

Loki snorted at the somewhat sarcastic comment, lifting his chin and watching intently as the Master took a step forward, almost immediately sucked into the whirling vortex. He glanced towards his remaining companion, who only widened his eyes.

"Ladies first," Lucifer purred.

Scoffing, Loki stepped forwards, towards the spatial phenomenon. The very world seemed to bend, and a wave of dizziness washed over him, so powerful and disorienting that it took him a long moment to realize that he was on solid ground, half-kneeling and half-crouching, his stomach heaving at the back of his throat. He squeezed his eyes shut for several seconds, struggling to inhale the dry, dusty air that he was confronted with, and waiting for his thoughts and senses to straighten themselves out. The first thing that he heard clearly was Lucifer's laugh, animated and mocking. Biting back his nausea, he unsteadily attempted to climb to his feet, ending up stumbling sideways and crashing rather heavily against the dark wood wall. His fingers sought purchase on the smooth, glossy panels, and it took him a moment to locate Lucifer's figure in the shadowed room. The fallen angel was sealing up the portal that they had presumably arrived through, flicking his fingers and closing it without leaving so much as a seam in the empty air.

"Lightheaded?" he teased, turning around and bringing his hands together in a single clap, a clear gesture of triumph. "Here I thought that you were experienced with traveling to Earth and back."

"I have not had a thing to eat or drink for two full days," Loki spat back, trying to ignore the fact that his surroundings were still a bit wobbly around the edges. "Such a form of travel can be disorienting when one is at a particularly low state."

"So it would seem."

Another wave of nausea washed over him, and he found himself shuddering unwillingly, losing his bearings for a second before warm hands took hold of his shoulders, guiding him to a crimson-cushioned armchair, which he settled into gratefully, taking several long, deep breaths as the Master's worried face swam into view before him.

"Do you need food?"

He shook his head, a single motion that looked more like a twitch than anything else. "What the hell were you thinking, taking him on as an ally? He will turn on us—within a span of days, believe me."

"He was my only chance of escaping the time lock. If not for him, you'd be headed for your execution right now."

"Gossip, gossip," Lucifer taunted from across the room, his voice singsong. The Master stepped back, still looking vaguely concerned, and Loki gripped the velvety arms of the chair more tightly. The formerly shadowy room was flickering into full view now, as Lucifer stepped back from a suddenly roaring fireplace. The golden orange light illuminated a high-ceilinged chamber, all sleek velvet and dark wood, the floor layered with what was undoubtedly vintage carpet and a grand piano parked in the corner, under a decadent but unlit crystal chandelier.

"Well, isn't this extravagant," said Loki, trying to keep his tone at least somewhat condescending. Lucifer just raised one dark eyebrow, snapping his fingers before sipping from a slim glass of wine that had suddenly appeared in one hand. Loki's parched throat seemed to cry out at the sight of the dark scarlet liquid, and he couldn't hold back a dry exhalation of desire.

Lucifer chuckled. "Thirsty, God of Mischief?" Before Loki got a chance to respond, he waved his empty fingers, and the air above Loki's armchair melted into the shape of a slender-stemmed glass, which then filled itself generously with clear water before floating into his waiting hand.

"I do think it best that you not consume alcohol when your focus is already this low," he commented lowly as the god took several desperate gulps. The glass obediently refilled itself once he had emptied it, and Lucifer and the Master watched on in incredulity as he drank for at least a minute straight, swallowing mouthful after mouthful before finally sinking back against his chair cushions, a curtain of tiredness falling over his face.

"Incidentally, I haven't been able to… sleep for the past two days, either," he got out, the words slurred with apparent exhaustion.

Lucifer just snorted. "Feel free to take a nap, O godly being, but I do think you might want to be around for your precious Jimmy's resurrection."

"…Moriarty?" His wintry eyes sharpened through their sleepy haze, and he straightened up slightly. "You're going to bring him back?"

"Now or never." Lucifer clapped his hands together, rubbing them quickly, and before Loki and the Master had time to so much as see what he was doing, there was an explosion of flame, a glowing orange pillar erupting out of the floor directly in front of Lucifer, hissing and roaring. Loki flung himself backwards against the chair, a hissing gasp escaping his lips, but the Master simply looked on, wide-eyed and with a manic smile to match Lucifer's curving the edge of his mouth.

"Jim," the Time Lord breathed.

Slowly, a dark figure became visible through the fire, which, though it generously radiated heat, didn't seem to burn any surface it touched. A few seconds later, it condensed into the definite shape of a slightly shorter-than-average, sleekly slim human. The flames flared, quickly and briefly, shining white just long enough to illuminate the silhouette's wicked smile before dying down into ash.

Standing there, his appearance pristine and polished, was Jim Moriarty, criminal mastermind. In the sudden silence, his smirk widened, and he tipped his head forwards in a slight nod.

"Master… Loki."

"He brought you back," Loki rasped in amazement. "He… he really did bring you back."

"So it would seem…" His gaze drifted to Lucifer. "Satan himself, or so I hear. I'm a big fan."

"James Moriarty," Lucifer murmured in response; "it is a pleasure."

"Mutual." They shook hands briefly, Moriarty's slender fingers practically crushed inside Lucifer's heavy ones, as the Master and Loki looked on in barely-suppressed awe at the resurrected psychopath. After a long moment, the Irish man turned to his allies, his arms wide and a large beam spread over his features.

"Now, I presume there's a reason for all this, and you didn't just drag me back because you missed my pretty face?"

"The same goal as always," the Master explained. "The Doctor…" His voice twisted into a low growl. "He's still out there. And I believe that Lucifer has a certain grudge he wishes to fulfill, as well."

"Dean Winchester," the tall brunette agreed. "Handsome devil's survived a lot more than he's worth, and it's about time that his trip to Hell become one-way. Not to mention, there's a certain angel whose skinny ass I'd just love to smoke."

"Well, our plates are very full, then, aren't they?" Moriarty mused. "Let's just hope that darling Sherlock stays dead."

"That's not all," Loki interjected, his eyes still not losing their fevered look. Cold sweat stood out on his dirty face, emphasizing its pale tone, and his chest was heaving with swift breaths, his knuckles straining white where he gripped the arms of his chair.

"Ah…" Moriarty looked him up and down slowly, giving a small nod. "Your brother still causing trouble, I presume?"

"More so than ever. But he has… allies this time," he sneered delicately. His head jerked as if to dislodge something on the ends of his hair, an odd tic that the Master and Lucifer were beginning to recognize as quite common. "A whole group of them."

"Does he now?" Rather than being upset by this, Moriarty looked rather delighted at the prospect of a new challenge.

Loki's chin tilted in a shallow nod, and his tone was contorted with more hatred than ever as he spoke his next words.

"They call themselves the Avengers."