Disclaimer: The Dark World was so good that I don't even care that I don't own it.
Don't read if you don't want spoilers, okay.
Sif goes to the water, to high and rushing falls that crush salt-rock into sodden sand and lick Sif's boots with frost-dagger tongues.
We found a body.
She had shuffled and sighed upon hearing the news. The Warriors let her be; but Hogun, returned to pay respects to the queen, watches her closely. She seeks Thor, gone to battle, but he remains on Midgard; so she stages her own skirmishes instead, blade after blade embedded in stone. Sif thinks of the glory and fire that had sent the queen to rest, the songs of sadness and love, and hurls a knife into the falls. She knows no dirges will be sung for Loki.
The darkness binds her, thick branches at her eyes that hang twisted from Níðhöggr-ravaged trees and Níðhöggr-ravaged forests that fade in a boy's dark hair—a shadow-voice. Not Thor's boastful crow, or Volstagg's great cough, or Fandral's playful lilt. Not Hogun's quiet wisdom, softly consoling in grief. Not Loki's silver words. Not anymore.
Sif.
She slumps against one of his spindly trees. She takes her sky-dark hair into her hands and remembers the spell that made it so. She knots her fingers and kicks sand since she has no more knives to throw. She listens to the water—water that moves like him, that sounds like him, that tastes like his salt. Water that rolls like his body and clings wet to skin, that sighs like their breathing harsh then soft, that swallows Sif cold with icy lips.
She remembers his presence on Odin's throne, gold and gold, a silent stare and a brief play at the corner of her lips. She remembers their war, words into and words between them, red body-paint and Sif's nails gouged into his hips like embers. Remember.
It's a subtle fury, their tangled bodies, their growls, stolen breaths and Loki's fingers worshipping her breasts, her bones. Words from a lovely and talented tongue, silk and silver between her thighs.
"You are despicable." Quiet, precise, punctuated by little gasps and long scrapes of teeth into Loki's shoulder, his throat, the edge of his lip. "You deserve nothing more than death."
"And what of you, who would bed a prisoner?" His soft laughter at her breast, his metal heart beneath her fingers. She smiles like a cat and pulls his hair, because Sif loves war most of all.
"Thor composes himself even now," she sneers, but the words taste like ashes. "You and I will see him crowned, and his mercy will decide your fate."
"Blind faith doesn't suit you." Breathlessly.
"I love him," Sif says, and bites his tongue.
"Sif," he whispers when they part, but when she pulls him into her it's Loki's name that she curses.
"Loki"—curses again, again, and the water shrieks like the death of a king. The knives, her knives are gone. Without the security of steel there is only sky, distant worlds and bodies lost to time and space. She's a child and a boy with raven hair grasps her hand before stealing her biscuit. A young warrior and in love with gold. A woman, lithe between his sheets. Somewhere in time his silver had lured her in a chase to Hel, and Sif never could resist a challenge.
Her knives are gone. She raises a hand and sinks her nails into wood and screams.
"Lady Sif!"
The dark world binds her. She brushes sand from her boots, lifts her claws from the stiff neck of the tree. Fandral laughs nervously and swoons and claps her on the shoulder as he always does. Volstagg shakes his wild head and helps her along. Hogun eyes Sif and nods—like always, but this time there's a profound sadness in the sharp corners of his mouth, and perhaps it merely takes losing something twice to see truth.
"We will remember him as a prince," Hogun tells her gently, but Sif remembers a warrior. And Sif loves war most of all.
She grasps no one's hand in hers and walks. I love him. A shadow licks her ear, whispers in Loki's voice. She bites back a retort she'll never use again.
Only this time, the words are different.
Níðhöggr = giant worm dragon thing that chews on Yggdrasil's roots.