The intruder slipped unbidden into Asgard, skulking in the black shadows. His mere presence threatened war, and the desire in his heart was darker than the shadows, and the longing inside him greater than the deep and all-embracing ocean.
Skillfully he did enter Asgard, and slip past her sentinels, and make his way to the prince's chambers. And when the intruder saw that which he most desired before him, his hands trembled and his breath near to left him. As he reached out to touch the handle of sacred Mjolnir -
"Have at you!"
Thor caught the intruder's hand in his own, sending him sprawling. With strength bore of shock and terror, the intruder kicked out at him, knocking Thor back a step, then tried to claw his way to freedom. But Thor was on him in a moment; the intruder struggled beneath him, caught fast in Thor's grip.
"Hell-bolt! Ah, but no, I have captured a Jotun!" Thor's face cracked in a smile, his teeth very white and sharp and his eyes very blue and sharper still. "And you're the runt of the litter, I see."
The intruder stared up at him fearfully through blood-red eyes. "I am a prince of my people," he gasped out at last.
Thor regarded him for several moments. "So I have captured the best blooded of devils! Do you mean to be ransomed, princeling?" he asked. "What price would King Laufey pay for his only son?
"Nothing," said the intruder. "He would have me die before paying a ransom. And I would rather die than be shamed or bound in chains. I wished only to glorify myself, Odinsson. To bring Mjolnir to my father would be to lay all the riches of the nine realms at his feet." And he cringed, and turned his face away.
Thor sobered somewhat at hearing that. He saw that this prince was in truth a runt in the eyes of King Laufey, and though Thor had never borne a moment's sympathy for any Jotun, he felt keenly the desire of the son to crown his father's life. "I would know your name, Grendel."
"Loki," whispered the Jotun princeling.
Thor braced his weight on him, needing little more to hold Loki down, catching Loki's wrists in one great hand and catching Loki's chin with his free hand. "Then look on Thor Odinsson, and know who you meant to despoil!"
He wrenched Loki's face forward to look on him, but even as Loki's red red eyes raked his face, Thor's own attention was captivated by the affect his own hands had on Loki's skin. Where Thor touched, Loki's skin warmed and took on the hue of a man, as though that color had hidden behind the blue and waited to be coaxed out. Thor swept a thumb over Loki's lower lip and shivered when the lip became warm, a lip that might tempt a lover, or a god.
"W-what are you doing to m-" Loki said with breath so cold that blackened Thor's thumb, but Thor lowered his face and laid his mouth over Loki's, and kissed him, and breathed into him, warming him from within.
Loki's reaction was instantaneous. He arched up against Thor, crying out with a sound that was raw and frightened and aching all at once, the sound of something brought to life, new to the world and needful. Never before had someone kissed him. But Thor kissed like he waged war, and if Loki had possessed any defenses they would've crumbled in a moment. Thor's hands pawed at him, and Thor's mouth breathed warmth into him, so that after some minutes Thor looked down upon him and Loki gazed back with eyes of a most jealous green.
"You cleaned up a beauty," Thor marveled aloud. His blood pounded in his ears; he'd never expected to clasp a Jotun princeling in his arms, much less desire him. But it seemed to Thor that he had never desired anyone so much as he did this changeling.
He pulled Loki into a half-standing, half-kneeling position and held him tight to himself, Thor's lips finding the place where neck and shoulder met. Loki, who had never known a lover's touch nor a moment of warmth in all his life, proved a quick study. If he could not hold Mjolnir in his own two hands, then perhaps he might master its wielder.
Loki's fingers trailed down Thor's arms, prickling his skin with the softest touch of fingertips, followed by the slow scrape of nails. Jotuns knew little of pleasuring the flesh. Their couplings were for the practical purpose of engendering offspring; Loki Laufeyson, Loki Too-Small, was never desirable as a mate.
But he made a match for an Asgardian, as Thor Odinsson was discovering. Their mouths met again, Thor's hand cupping the back of Loki's neck. When they pulled apart, Loki slid his eyes shut and brushed his face to Thor's, feeling the scratch of Thor's stubble on his newly soft, man-like skin, the brush of Thor's lashes against Loki's cheek.
Thor felt intoxicated, as though mead-maddened by Loki's kisses. He clambered to his feet, pulling Loki with him. "I would have you to bed," he said. "For this night, and as many nights as we have before us."
Loki looked down at his hand, and in the flickering candlelight he could see the blue bleeding through around his fingertips, spreading upwards to his wrist. He grasped Thor's hand in his, and the blue retreated once more. "I am no concubine to be kept by you," he told Thor. "I would share your bed, but how can I remain by your side?"
No one had ever truly denied Thor anything. A flash of anger swept through him like a thunderclap. "Who would keep you from the Odinsson! If Jotunheim has walls, yet would I breach them, and if your father has arms, yet would I break them."
Loki watched him thoughtfully, as though taking his measure. "Then let me come and go as I wish, and I will come to you willingly. For Asgard has walls, and yet I did breach them, and your father has arms, and yet I did avoid them, and if you are here waiting for me then nothing would keep me from you." And Thor's arms clasped around his body, and Loki leaned in close and laid his head in the curve of Thor's neck, and felt his heartbeat.
"Stay with me this night," Thor pleaded. "And then go as you wish and come as you wish, and I will be a-waiting you."
He led Loki to his bedchambers and they tumbled down into a pile of furs. Loki desperately hoped that Thor knew about the ways of lovemaking, for he knew naught at all; and Thor held him and stroked him until Loki tossed his head and cried aloud and bit his tongue to kill those cries. Thor laid behind him, and thrust between his thighs and touched him between his legs, and the world went white and both were senseless.
After love, Loki draped himself over Thor, combing his long hair with his fingers. "The hour grows late and I must be off," he told Thor regretfully.
Thor slipped his pendant over his head; it bore the sigil of the Thunder God. "Wear this when you come to me," Thor said, "so that I may know you in your other form." And it was Loki who kissed him first and drank him down eagerly.
He slipped from the bed and dressed himself in his simple garb, and though Thor was asleep before Loki departed his chambers, he did not bother grasping Mjolnir's handle again. There would be opportunity for that, and more, later. Loki magicked himself between worlds, and when he arrived in Jotunheim he was blue-skinned and red-eyed once more, and the cold wind blasted the warmth of Thor's touch from his skin.
Loki went at once to his father, King Laufey, and knelt at his feet. And when Laufey beckoned, Loki showed him the pendant he wore around his neck.
King Laufey was astonished. "You have this from the hand of the Thunderer himself? You have found his weakness?"
And Loki smiled, and the smile spread, curling back his lips and showing his teeth, and he said, "Yes, I know his weakness."