This is just a one shot in response to a 30 minute challenge by a friend...
Severus Snape carried the woman through the forest. He'd been carrying her for two days now as he'd refused to levitate her. No, this was his burden and he needed to feel the stinging agony of the pain it inflicted on his body in an attempt to ease the pain that burned through his soul.
As he walked he remembered the day she'd come to him. Once before he'd shunned her interest and yet she refused to take no for an answer. The woman had found him alone and disrobed. She'd seduced him with her body that night and enticed him with her soft spoken intelligence ever since. For three years she'd stood by his side through the good and the bad, loving him in a way he'd never though possible. Three years to the day he'd married her, this creature who'd given him far more in life than he'd ever deserved.
Finally he stopped for the night and lay her body gently on a soft bed of leaves. A small crackling fire started with a flick of his wand and the light it emitted cast eerie shadows over her lovely face.
As he watched her Snape shook with fury as he recalled the last battle. He'd tried to keep his wife out of the throng but the Gryffindor in her demanded that she stand strong by his side. If he'd been a man, a husband, he would have forced her to remain behind. Voldemort had been defeated two days past. He'd felt the sting of Snape's own curse only to be finished off by a blast from Potter.
Relief had begun to sink in as he took his wife's hand until the shadow of Lucius Malfoy approached. Malfoy had called him a traitor and as the Potions Master prepared to face death by his wand his angel of mercy stepped in front of him to be felled by the blow. She died in his arms. His wife passed from this world protecting him. She had loved him more than her own life and to the Potions Master that was far more than he deserved.
Self pity and loathing washed over him. He'd not deserved to have someone love him so completely and unconditionally. He'd been mean and cruel to her many a time and always found forgiving solace in her soft arms. His wife had given him her very soul. She'd given him her body in the softness of caresses as well as in the bold force of his carnal desires.
On the third day he carried his burden until his legs buckled and then, only then, did he Apparate them to the cavern in the mountain.
Heavy ice crystals sparkled like diamonds on the walls. They hung like brilliant chandeliers from the ceiling. The brutal cold did not faze the man as he set to his task.
He eased her body to the floor gently before lighting candles about the cavern. With a flick of his wand the small pool of ice melted into a crystal clear reservoir. Fingers created a slight ripple as they slid across the frigid surface.
Severus gathered the still form of his wife close to his body one last time before laying her in the pool and casting a spell to freeze the water.
Silently he gazed upon her beautiful face until his very bones felt like they would freeze from the cold. "I love you," he spoke softly, wishing that he'd had the courage to speak those words to her in life. A shaky hand blue from the cold glided over the icy surface. It moved as if trying to caress her cheek down to her womb where his son lie. A bitter laugh escaped his lips as he thought of the child who had never lived to breathe it's first breath.
As he mourned her his bitter agony turning to a dark hatred that radiated from his frigid body, Severus Snape made two vows. The first was that he would personally hunt down and kill each and every remaining Death Eater left on the planet. There would be no place they could hide that he could not find them, and kill them slowly out of revenge for what had been so dearly taken from him. The second was that he would not rest his weary soul until he found a way to bring his beloved back to life. There were many means, most of them very dark and powerful magics that may not be beyond his reach and he would find a way!
And so that day, three days after the fall of Lord Voldemort, a new Dark Lord was born.