Written for a Loki/Sif contest back in June and posted to my tumblr. I most certainly did not win but I feel like dumping all my tumblr fics over here anyway :)
Heimdall has always held a great fondness for his sister, the warrior Sif. Born to one of his nine mothers centuries apart, the sentry watches her life unfold from his post at the edge of the cosmos. He watches her grow, watches her as a child fight for the right to study and train within the walls of the palace. The gatekeeper feels great pride in her bravery, standing strong in the face of those who taunt and ridicule her with her chin held high. Although Sif does not name him, Heimdall takes note of the dark haired boy who pulls her hair and steals her quills. He smiles when she knocks him to the dirt, unafraid of his status as a prince and affording him no special treatment. And when she rides out to the observatory to sit at his feet, he lets her hide her tears, turns his gaze to the branches of Yggdrasil and tells tales of the great adventures that await her.
The guardian watches as she continues to rise, the spindly arms of her youth growing strong and lean under the weight of her sword and shield. Her visits to the end of the rainbow bridge are filled with less tears and more tales of accomplishments, and for that Heimdall is glad.
Sif finds her happiness in the training yard, soon catching the attention and respect of the golden haired prince and his friends. But still, Loki continues to be a dark spot in his sister's shining glory. Heimdall takes note of the jealousy that flares in the second prince's eyes when Thor invites Sif to join him in feasting and fighting, seemingly enraged that his brother affords attention to another and particularly to a shieldmaiden.
He is a sneaky thing, the boy, preferring to fight his battles in shadows and with his forked tongue. And still, he seeks out the warrior maiden, taking obvious joy from stoking Sif's ire. He antagonizes her, pushes her with his words alone until she has enough and retaliates with force, at which point the prince is sure to cry innocence, citing her poor temper and eagerness for brutality as faults.
Heimdall does not trust the prince, has watched for centuries as he spins webs of lies across the palace. He finds comfort in the fact that when Loki stands, shifting uncomfortably, within the observatory accompanied by his father or brother, he is unable to meet the sentry's knowing gaze. Heimdall sees his tricks, is witness to the chaos he causes, knows acutely of the hurt and suffering he sows.
As they grow older, the animosity between his sister and the prince does not diminish. The cutting stings of their barbs grow more acute, more deadly. Loki mocks her loyalty, insults her honor. Sif sneers at the prince's cowardice and his jealousy of Thor. Heimdall sees how they can hardly stand to be in each other's company, how each brush of skin between them is like a burn, instantly recoiling from the other's touch.
He watches it build between them, until hardly a day passes without the Silvertongue pushing her to breaking, their arguments coming to blows in the training yard long after everyone else has retired for the day.
Loki uses his magic, illusions and smoke to dance just outside her grasp, to frustrate her until he can sneak up from behind to push her to the ground. He pins her to the dirt with his hips and his hands at her wrists, hisses vitriol against her ear.
Sif overpowers his willowy form, attacking with animalistic fury. She instructs him to stay away from her, where he is bruised and bloodied on his knees before her, a fist in black hair tilting his head back so she can practically snarl against his swollen lips, her blade against his throat.
Heimdall knows that Loki is not to be trusted, but he is also certain that Sif can take care of herself. Still, he cannot help but worry at the way the dark prince seeks her out again and again. He sees the jealousy in his eyes over Thor and the love for mischief within him. Loki's magical proficiency grows stronger and Heimdall fears that he is capable of things none of this realm have accomplished in ages. As each day passes, the shadows around him darken, blurring his form. Even when Heimdall fixes his gaze directly upon the liar prince, where he is hunched over ancient tomes and scrolls, he seems to flicker and fog. Loki is concealing, deceiving, and he is planning something, though Heimdall knows not what.
Loki is dangerous, yes, but he never truly fears for his sister. Until the day he sees her traveling down a palace corridor alone. She does not see it coming. Stepping out of a shadow behind her, Loki attacks, slipping one arm around Sif's waist while his other hand covers her mouth preventing her from screaming. Heimdall only has time to see her eyes fly open in surprise before the trickster wraps them both in shadows and she is gone.
The gatekeeper focuses his sight, searching all of the Nine Realms for a sign of her but finds none. Loki has stolen her into the darkness, hidden from his sight. It matters not, he will tear Yggdrasil herself apart to find her.
Blind with fear and rage, the guardian races across the bridge towards the city, his mighty sword drawn as he runs. Long, too long, it is taking too long. He pushes past all those who do not move swiftly enough out of his path until he is inside the golden walls of the palace, not slowing his pace until he reaches the spot where he last saw her in the long corridor not far from the Royal family's chambers. From his rooms. Heimdall stalks forward towards the great glimmering doors of the prince's living quarter, pressing an all-hearing ear against the cool gold.
He hears her voice, hears her scream and his great sword is slicing through the door. With his sword still raised he bursts through, his golden helm shining as brightly as the fire in his eyes. He cares not that it is treason against the House he is sworn to protect, he will tear the bastard limb from limb.
It is obvious that a struggle has taken place for the antechamber is in chaos. It appears that Loki's desk has been overturned, books and papers litter the floor. Heimdall spots one of Sif's knives on the ground, torn clothing scattered around it and his heart drops as he rushes further into the quarters. He hears her shout again and a low hiss from that snake follows and he pursues the sound, slashing through another set of heavy doors.
He stop short when he sees his sister's naked form atop of the trickster, her dark hair spilling down the long line of her back and the prince's long hands wrapped around her hips. Hips that are pressing him down into the grand bed. Her head whips around at the sound of Heimdall's sword clattering to the ground.
Her eyes are wide in surprise as she rolls to the side and Heimdall charges towards the bed. With a thunderous roar he reaches for the prince, who is frozen in panic, blatant fear upon his face. Grabbing Loki by the neck before he can slither away, Heimdall wrenches him naked from the bed and holds him at eye level.
"What have you done to her?" His low voice drips of fury.
"Nothing that she did not enjoy, I assure you," Loki gasps, his long fingered hands wrapping around Heimdall's forearm, struggling to find purchase.
"Under what spell do you have her? Tell me at once, Trickster!"
A strangled laugh leaves the prince's lips. "No spells. No tricks. The Lady is here of her own free will."
"No." Heimdall's grip tightens around his neck. "I saw you steal her. She hates you. And you hate her. I've watched you for centuries."
"Yes, well, looks can be deceiving," Loki manages a smirk despite the frantic straining of his toes attempting to keep contact with his floor. "As odd as our courting rituals may seem to some, I find they suit us quite-"
"Courting?!" Heimdall bellows, furious at the liar's games. "That is the way you choose to woo a lady, through insults and abuse? No. You do not deserve to touch her."
Loki blinks at the gatekeeper's words, the smirk wiped from his face. "I know."
"I believe I will be the judge of such matters, Brother."
Heimdall suddenly releases his hold from the prince's neck, as if he's been burned. Turning to his sister, now wrapped in a golden sheet and looking rather unperturbed, she tosses a pair of trousers towards Loki as he stumbles to keep his balance, gasping.
When she turns her gaze upon her brother, her eyes are battle fierce. "While I do thank you for your consideration regarding my well being, I am more than capable of handling suitors myself."
"How long? How long have you been, been courting? How long have you been laying with this snake?"
"Well, I suppose I realized that Loki's attempts to gain my attention by whatever means necessary were not purely malicious a decade or two ago. Juvenile, yes, but not truly hateful nor unwelcome." Sif mused nonchalantly. "And I decided I enjoyed his particular regard not long after. You do know how I love the thrill of a good brawl, dear brother."
"And as for how long this particular, uh, physical aspect has been taking place, well you are witnessing the first time." Loki speaks to the ceiling, unwilling to meet the golden eyes of Sif's brother.
"But now that you are aware of the circumstances, I will thank you for affording me my privacy." Sif levels him with another sharp look, which he meets with his own burning stare.
"This is a mistake, Sister. It would be unwise to trust the Silvertongue."
"I never said anything about trust. And it is my mistake to make."
His hands clasped innocently behind his back, Loki bounces on the balls of his feet. "I think you'll find that she is quite fond of my silvertongue," he quips, a smirk once again pulling at his mouth.
"Shut up, Loki." The shieldmaiden punches him in the arm. Loki grabs for her wrist, tugging her closer until her body knocks against his. He peers down at her, maintaining his grasp on her wrist.
"I see that violence is a family trait." Sif rolls her eyes at his leering.
Suddenly eager to return to the solitude of his post, Heimdall bends to retrieve his sword, aligning its tip at Loki's chest as he rises.
"And you would do well not to forget it. Know this, I do not like you, I do not trust you, and I do not like this thing. I have my eye on you, Liesmith. And if you hurt her, I will come for you again."
Sif clears her throat and Heimdall throws her glance. "If she does not kill you first."
The warrior nods with a satisfied smile at that. Pulling her wrist from the prince's grasp, she walks her brother to the ruined doors and plants a warm kiss to his cheek with a chuckle as he departs to return to the Bifrost.
Standing upon his golden steps once more with all the branches of Yggdrasil dancing before him (but deliberately avoiding seeking out his sister), Heimdall shakes his head in confusion. He looks back on the relationship between Sif and Loki, all of the fighting, all of the sharp looks and sharper words. A great sigh leaves him.
This was one thing he did not see coming.