If the first night had been measured in shadows, so the second is measured in light: in the slivers of torchfire that cut across her cheek, the vivid glare of metal reflected in crystal, the emerald brilliance of his eyes.
Sif is ever-resourceful, a trait which did not fade in Loki's absence: her breeches leave her body quickly, offering tribute to the shadows with an aimless kick. She hasn't the patience to meddle with his trousers, and claws at the fabric in a haze; the cloth snaps in protest, threads splintering beheath her hands, and he strives against his own restraints.
"Onto your knees," Sif says quickly, a fine tremor seizing the voice which Loki knows so intimately, unabashed and hoarse and sharp as a blade. He scrambles and she grunts, pulling him up gracelessly into the desired position. He kneels before her because power is a thing hoisted and squandered by gods, and the subjugation of lesser beings is something which Loki well understands.
She reaches and bunches his tunic in her fingers, as though repressing the urge to rend it with her hands; then yanks it upward past his sternum, dives down to strike with her teeth.
She worries a particularly gruesome-looking bruise with the dagger tip of her tongue, just below his heart, before pushing hard into the blued flesh. Spots of pain prick his eyelids, brush the length of his arms like a blanket of thorns.
She is war.
"What is it, shadow-prince?" she bites flush into his neck, sucks claim into the flesh, and her nails are a merciless vice. "What ails you? Surely you will not submit so easily—or is it only the harmless Midgardian mortals who incite your hand?" Sif draws her palm along the length of her thigh, commanding his gaze as she brushes calloused fingertips over her folds.
He nearly speaks then in spite of the muzzle, but the words tangle like snakes within his throat: sunken, vacant, coated in the slick of saliva, pitched and fallen flat along with his screams.
"Coward," she whispers, because she knows that she is—that they both are—and arches her body taut against her fingers.
Loki knows these sounds, he knows intimately the movements of her body as it reacts when he's magicking her with his own fingers, because it's ground captured and chartered and studied more thoroughly than the mischief god would ever venture to admit.
For her to reach climax takes no time at all, and Loki revels in the small victory of a weakness brought to light, just as her skin glows ruddy beneath the latitude of countless forks of snickering flame.
The stone irritates his spine, grating the nerves, and Sif's expression is indecipherable as its ingrained grooves. She leers over him, toward his own impatiently-bared erection, which arches fruitlessly against cloth. And she glares, because the wicked smile she's trying to execute fails with the effete muscles at the corners of her lips. A small loss, but one Sif cannot afford.
So she leaps up. Snatches her discarded clothing from the floor in a blaze of torchfire. Dresses.
And leaves.
She barely remembers bringing the captive his food the following day.
She barely remembers anything at all of the day, save for a few stubborn tidbits. The wolfish grin of Volstagg as he swirls his morning mead; the great gray bird sweeping the sky over her head as she spars with another warrior; the consoling hand of Thor, which had confirmed their mutual sadness over the issue which currently rests hunched against the clear walls of a dimly-lit enclosure.
They hadn't spoken when Loki was brought to the palace and they've not spoken since—not of the prodigal prince, not of his plight, not of past or of future. Their conversations instead take place in the language of dampened glances and kind gestures, and in heated matches carried out at the break of dawn, where they exhaust the frustration through furious blows which render their blades dull.
Sif's body throbs with a fatigue that only worsens as the sky shifts into its evening hues, into a nightfall marked with a smattering of stars—some which twinkle with splendid brilliance and others remaining motionless, envious of the beauty of their peers.
Her head swims with light, piercing light, green light which comes in spikes someplace behind her retinas; she stumbles over a wayward crag while making her way back to her rooms from the warrior's grounds, catches herself deftly, silently grateful for the lack of witnesses.
She doesn't think of him because he is already inside her mind, and the ability to think is a luxury compared to the presence of this shadow—of a criminal, a king, a god. Instead she traces a nail down the cold, smooth surface of one of her knives, and does not ponder its likeness to his skin, even now, even now.