He hears the dim scream of battle over the rushing of blood out of his body. The boy and Granger have left, taking his shame and his most precious memories with them. He closes his eyes against the pooling darkness. It will seems like minutes/hours/days before he feels the tug of his soul exiting his enfeebled and hated body.
Even though he expected this end, he doesn't want to die. Not really.
He doesn't so much awaken as he is in an area that is filled with diffuse light. He recognises the washed-out landmarks around him. That swing set is where he first confirmed that Lily was like him… that copse of trees is where they spent their summers before that last disastrous comment… that road leads to his miserable childhood… the other to her family…
He becomes aware of a scintillating warm presence coming towards where he exists in this brightly lit underworld. He has no illusions that he will receive a reward for his service to what Albus termed "the Light." He failed in that. He knows he did because as his hearing faltered in life, he heard the Dark Lord give the boy a choice, and Severus has no faith that a certain seventeen-year-old will make any better choices than Severus did when he was young.
Death is not an entity to be embraced lovingly at any age but the most ancient. It is obscene to expect a child to do so.
The figure draws closer. Although he cannot look on the shape of the being directly, he knows that it is a woman of great beauty and fearful horror that comes to him. Her features are at once fixed and fluid. She is many things at once. Severus recognises her from her cloak of raven feathers and the acrid stench of bile, blood, and the fear that one only knows from battle. She is The Morrigan, and she's come for him.
He cannot look on her even though he knows her face intimately, twenty years of war will give a man that kind of sight to see a goddess of war. So when she holds out her hand, at once cadaverous and plump as a stripling girl's, he hesitates only a millisecond. He sealed his fate when he took the Dark Lord's cursed mark, when he chose to pervert his magic into a twisted dark thing. He's expecting her hateful embrace.
What he doesn't expect is her melodious laugh or the lightness he feels in it. "Don't let's start out with any misunderstandings, Mortal. You are not mine/ours. Not yet."
She waves her other hand and the bright white mists clear. His body is as he left it in that stinking shack, twisted, bloody, and fragile. A form hovers over it, a version of The Morrigan, a particle of her being, at once different. "I am/We are here in this place and the one beyond. I/We have come to strike a bargain of sorts with you."
Severus watches in the place beyond, the filthy shack that was scene to so much of his personal horror. There is a woman that he recognises as Macha, a lush and fecund goddess, but tainted with a underlying vileness. She looks as if she's the warm earth above and the festering monstrous constructs below it. As she touches his face and his neck, she sings a song of making and unmaking. He feels the faint whisper and heat of her touch against his phantom self. The battle crow, Badb Catha sits on her shoulder cawing impatiently. After some time Severus remembers The Morrigan who holds his hand in a disjointed type of memory. "What is your bargain, Madam?"
"Such impatience." The Morrigan waves her hand and the scene beyond dissolves back into white. There is a buzz of irritation in her voice. In the distance an infant cries piteously and over that Severus can hear two voices talking. He can't make out their words or who they are, but they are familiar.
The Morrigan says, "Very well. I/We give you two choices, my/our Prince." She holds up her finely sculpted, claw-like hand, one finger thrust up, "The first, you may choose to die this night, unmourned. If you make that choice, you will immediately return to the beyond as an infant to relive your mistakes until you learn the lessons you should have in this life."
She holds up another finger, forming a V with the two digits. "The second, you may choose to go back. To do that, you will live under a geas, one that if you break will result in your immediate death where you will be my/our slave for eternity, a state to which I/we know you are accustomed if not quite comfortable."
He knows she looks at him, the heat of her gaze burns the skin it touches. He says after a moment, "And if I do not break your stricture?"
She bends to him, finally drawing his own gaze to hers. Her eyes are the black of the darkest void, they are filled with triumph and despair. There in the black is the knowledge of all things in creation and chaos, they will let him go mad if he chooses. Her crone's smile curves into a supple bow of mirth, her teeth are white, her lips full and red, her skin is satin over a framework of decay. He finally tears his eyes from hers with a sickening whimper. "If you do not break the geas, you may live your life as you see fit, and when you come to the summer lands, it will be as a sovereign, a king, if you will. I/We will be as old friends, and you will feast at the table of warriors, bards, and kings. The glory you so richly deserve will be granted in both life and death."
She lets go of his hand and suddenly he is bereft. "You must decide quickly. This day's candle has nearly come to an end."
As if on cue, the bright world shakes and dims, the infant in the distance gives a final howl and is silent. "The geas, Madam, I would know what it is before I choose."
Suddenly next to her is a ragged wolf. It is unblinking, yellow-eyes and half starving, a fearsome creature of massive height with strong, rangy muscles. As she pat's the beast's head absently she says, "You know that is not how these things work, mortal. Choose now and then I will tell you."
Without thought he says, "I choose to live."
He wants to take back the words, but they are wrought in far stronger magic than he can conjure.
She bends gracefully at the waist and draws a knife over the hapless dog's throat and then butchers it. When she has relieved the still twitching creature of its skin, she turns back to him. She places the steaming, bloodied pelt around his shoulders and full purse in his hand. He feels the stricture of the geas settle on his shoulders as she does, heavy as Atlas' burden. As the pelt sinks into his skin, she says, "What is agreed upon is bound. What is said, so may it be. You will return to life, but not as you were. You will appear as twisted and ugly in the mirror as you think yourself to be. In that time you must convince the one who would deny your humanity to accept what and who you are. At the end of the seven years if you fail, you will die."
As the words are spoken, a bell peals in the beyond and once again the bright world shakes. The woman with the crow materialises beside the Morrigan. All three creatures say, "It is done. Live as you will Severus Snape."
Severus awakens to agonising pain and weak limbs, but he is alive as The Morrigan promised. The world beyond the walls of the shack is quiet. He knows his time is short. If Potter did as Albus hoped, the Dark Lord is dead and Severus will pay for his betrayal to the light. It does not bear thinking upon if Potter failed. Either way, he must flee. He has a new, if more selfish, quest and only seven short years to accomplish the deed.