A/N: I've never actually seen Blues Brothers, but I kinda suck at titles, so it'll have to do. ^^;

Chapter 1

Outside their dim cave the wind howled, ice and snow blotting out the broken landscape of Jotunheim. Sif, Hogun and Volstagg tended to Fandral's horrendous wound, though it was Loki's meager healing magicks that had truly saved the warrior's life. Tucked away further into the cave, around a bend and safely away from even friendly eyes, Loki now tended to his brother.

Thor sat, mouth a flat, grim line, as Loki tended his sprained wrist. His brother's magic whispered through bruised flesh, cool and soothing, but he paid it no mind. How could he, when there were so many worse things to think about than a mere sprained wrist.

Monster. The thought beat in his head, growing louder and louder. Monster. Monster. "Monster."

Loki flinched, froze, head still bowed over Thor's wrist.

"I'm a-" Thor managed through gritted teeth. "I'm-"

"Thor. Stop." Loki's voice was harsh.

"Remove the illusion."

"Brother-"

"Remove it!" Thor growled as loudly as he dared.

The line of Loki's shoulders was rigid, his head still bowed. But then he looked up, and waved one hand in a short arc. Light danced off Thor, revealing blue-gray skin covered with smoothly curving scar-like ridges, and eyes red as blood.

"I am a Jotun," Thor said, voice thick with revulsion.

Thor turned his hands over, inspecting them. "I am a monster." Then he curled his hands into fists, and Loki's eyes narrowed. He knew that tone of voice; Thor was about to do something foolish.

Thor's hand shot out, grabbing Mjolnir's handle. Loki seized his wrist, pinching and twisting the sprained area, making Thor's hand spam open. "What are you doing?" Loki asked, deceptively calm.

Violence lurked in Thor's eyes, and anyone else would have been thrown across the cave. "A monster cannot hold the throne of Asgard, I'll not allow it."

"Killing yourself will not solve the problem!" Loki hissed, his fury a cold, empty space in his chest.

"How not?" Thor demanded, "Say I was killed by a Jotun, ascend the throne yourself, and rule Asgard as the wisest king the land has ever known."

Clearly his brother knew not how to tempt him. Loki laughed, a harsh sound. "And you say you would have no monster on the throne."

"You are no monster-"

"I am a Jotun too!" Loki forced the words out, anguished.

Shocked silence lay between them, Loki almost as surprised at his admission as Thor.

"No."

"Yes," Loki admitted, tears filling his downcast eyes against his every attempt at control.

"How long have you known?" Thor asked weakly.

"Since the battle. A Jotun gripped my arm during the it, and," his voice failed, air sucked from his lungs, "my arm became as a Jotun's arm."

"Another illusion, then?" Thor asked, and Loki resisted the urge to turn his face from probing eyes.

"No, there is no illusion upon me. The Jotun released me when I killed it and, and my arm returned to normal."

"Could it be some Jotun curse placed upon us?" Thor asked, and Loki hated to crush the hope in pleading red eyes.

"No," Loki admitted reluctantly, "they had only ice magicks. I would have felt any other." It was so damnably true, too. Loki had been horrified when his arm changed, but he'd still desperately hoped that there was some other explanation. When he'd seen Thor at the Bifrost site, pinned under the monstrous, bestial Jotun, blue leeching into Thor's shocked features, he'd almost broken down himself. Only imminent death had forced him to ignore everything except getting them out of there, away from the descending horde of Jotuns. And through it all, the Bifrost had stayed mutely, damnably closed.

Thor's shoulder's bowed for a moment, then straightened. "How is it that you are once more Aesir and I am not?" Thor asked, anger returning, accusation barely hidden.

"I cannot give you answers I do not have," Loki admitted.

Thor's half-disbelieving look was too much, and Loki felt something rebel inside him.

"You think I planned this? You think this some game of mine?" Loki hissed furiously, leaning into Thor's space. "That I know anything about this, this, travesty? You think I had the least inkling, the slightest idea that Odin had taken two Jotuns as his sole heirs?"

There, let Thor have an equal share in in the burden of what Loki had already deduced. Inches from Thor's changed visage, Loki met his Jotun brother's stare, heedless of the tear tracking down his cheek.

Thor rocked back, eyes widening as he took in Loki's meaning. "His sole- his sole heirs."

"I would guess that either Father or Mother is incapable of producing children. More probably Father," Loki said bitterly. Of course Odin was not their father, strictly speaking, but if he started quibbling that point with Thor now, they'd never settle anything.

"But…"

"Think about it. If Father could have children, why has he not? It undermines his fitness to be king. With both of us being adopted in, even if no one knew of it, it would make sense for Father to want a child – an heir – of his body. But he has none. He probably found us after the victory over Jotunheim. An Aesir adoption, no matter how clandestine, has the chance of being traced. If he knew he could sire no children, two Jotun babes – untraceable, never to be missed – would have been an almost-perfect answer."

"Almost?"

Loki's mouth twisted into something between a rictus grin and a grimace. "Except in the event our heritage was discovered. In which case..."

Thor would never be Loki's equal intellectually, but that didn't mean he was stupid. "Father would lose the support of the warrior houses. He would be disgraced, exiled at best."

"And who inherits then?"

Thor looked at him, blue face frowning as he worked through it. "Mother-no, she had to have known, they would never allow an accomplice like that the throne. We have no direct uncles, only a few distant cousins, all with an equal claim, mother's family has no immediate candidate…"

"Civil war," Loki murmured, confirming what Thor sought not to say.

Thor shuddered and leaned forward, resting his forehead against his brother's. Eyes closed, Thor let the gravity of the situation settle within him. "Asgard would tear itself apart."

Loki said nothing, giving Thor the silence he needed.

The golden prince of Asgard opened red Jotun eyes, defeat and acceptance settling there. "And if we die, even if our true heritage never comes to light, if Father can have no other children…"

"Father is old, ready to pass on the crown. While having no heir wouldn't be as immediately damaging as revealing what we are, it would create tension within Asgard and possibly destabilize Father's authority."

Thor nodded reluctantly. "We must find a way back to Asgard."

"And we must keep our heritage secret. None may ever know of it."

"Thor, Fandral is-" Sif's relieved voice hiccupped to a stop.

Thor sat, frozen, as Sif's alarmed gaze took in damning blue skin.

Loki spun around, summoning an illusory double of himself that made to tackle Sif as she turned to run back out. Without time to think, Sif dodged back instinctively from the lunging figure, giving Loki time to catch her around the waist, trapping one arm against her side.

Sif froze, head tilted back and held still in concession to Loki's glowing dagger at her throat. She had one arm free, but she didn't think for a second that Loki's tense alertness would let her make use of it.

"Loki, put that away," Thor ordered.

"Why, so that she can announce this to the others?"

"She is our friend, now you will put away your weapon," Thor demanded, pulling himself upright. There was arrogant steel in his voice, and Loki thought Sif's intrusion was almost worth its return.

"On your head be it," Loki allowed after a tense moment, letting Sif slip from his hold.

Hand to her throat, Sif glanced from Loki to Thor and back. "What trickery is this?"

Loki opened his mouth to lie, then stopped. If he'd played Thor's appearance off as a trick and an illusion from the start, it might have been different, but now only the truth, dangerous and monstrous, would do, for Sif was one of the few people who could sometimes spot when he was lying, if not what he was lying about. Loki cursed himself for being too rattled to think straight, but what was done was done.

"Nothing of Loki's doing. Nothing so benign," Thor said bitterly and averted his eyes, an unheard of show of weakness, "But my brother has a theory."

Loki was loath to bring anyone else in on the secret, but it looked unavoidable, so he ordered his thoughts and prepared to relate the events of the day in all their horrific glory. This was shaping up to be a most spectacular day, he reflected sourly, right up there with Ragnarok.