Warnings: Blood, violence

Notes: This story began with a simple idea: what if I wrote an EF AU where both Emma and Killian were Dark Ones? And now, about a year later, here it is! It is completely finished, and will be updated on Wednesdays and Saturdays. Endless love, devotion, and gratitude to ripplestitchskein, without whom this story would never have happened, and thanks to unfolded73 for reading this through, and giving me invaluable pointers. Credit to seethelovelyintheworld for the gorgeous cover. Title borrowed from the titular poem by Robert Frost.

Prologue

There was little that compared, Emma decided, to the weight of a blade in one's hands. When it was well-forged, the hilt balanced neatly between her thumbs and forefingers, the others joining just behind to caress the gilded handle. The filigree pressed arcane indents into the palms of her hands, swooping letters that spelled her own name, and another's. The blade itself was swiveled, leaping in smooth currents down towards the deadly taper, tipped up and out, the way her father had taught her.

Father, she thought, in many voices, most not her own.

The darkness was funny that way. It had crept up on her, taking insidious hold of everything she once held dear, twisting it until it was unrecognizable, the hollows left behind filled to brimming with hatred, anger, and single-minded pursuit.

Of what? Emma wondered, dazed.

Of power, a voice answered.

Of freedom, said another.

Love, she thought, wildly.

"Love."

Emma looked up. The sunlight, dim and hazy overhead, glinted dully off the blade in her hands. It danced in the shadows stretching out beneath her feet. A moment, and then she realized that it was because the sword trembled in her hands. Or rather, her hands trembled, harder still when she looked upon the man who stood opposite the hilt.

"Love," he repeated. "You know what you have to do."

The soil underfoot began to turn, and the limbs of the trees at his back began to quake. The ringing in her ears ceased, and the sounds of the battle raging down over the hill took precedent. With the grossly elevated reach of her senses, Emma could hear the crush of bones under hammers. Blood flow interrupted with the slash of blades, hearts squeezing futilely against the spill of red upon grass. It swayed unknowing in the gentle breeze of late spring.

A woman's hand was crushed, a battle horse lost its rider. A falcon cawed somewhere in the forest beyond, and thousands of critters were pushed further underground with the shift of her feet when she said –

"I can't."

Killian smiled. He smiled amongst the rage of battle, the loss of life and limb, the tang of fluids of life wafting into his nose. She could hear them, feel them, smell them, as surely as though she looked out from his eyes. Emma recalled, when she first saw him, the hollow ringing of his mind against hers, like two sharp blades fallen together, like –

"Emma, stop. You have to help me. Please."

"I can't," she answered, though she held the blade tighter in her hands. "Why should you be the one who dies? We didn't start this, we didn't – "

"It doesn't matter."

He paused, and took another step, then another, until the sword rested on his shoulders, his hook tangling in her hair, strands spilling wildly over her shoulders. He pressed his hand against her cheek, his fingers dragging over her jaw. Though the smile remained, resolute in the face of the fate that awaited him, Emma's face fell, tears flowing down and off the jut of her chin.

"All of the things I've done," Killian said, hand gripping tighter. "I succumbed to darkness, and I've longed to atone. This is my chance to be free, as much as it is yours."

"But – "

"Swan."

Emma quieted. Killian's feet nudged against hers, and she remembered vividly the last time she'd stood so close, hardly an hour ago, before the women and men on the grounds below had indulged in the pull of battle. One of the voices of darkness in her mind, furious in the face of its death, conjured up the image of rabid people drinking one another's blood.

"Emma."

She looked up, only to find Killian backing away. His nostrils flared, and she could smell the fear on his breath, could hear it in the shift of his bones. He spread his arms, and his hook glinted. Not menacing, but familiar, warming in the soft light.

"Please," Killian said. "It will be alright."

He took a deep breath, and looked her in the eye. The darkness, in all its multitudes, screamed in her ears, so loud it rose above the battle. But nothing – in all the realms, living or dead – could crescendo above the noise her heart made when he smiled wetly at her. Emma gripped the sword tighter, and held it level with his heart. She pulled back, and with a careful snap of her wrist, a thrust of her shoulder, the sword pushed forth, sinking neatly through his sternum.

The world around her, then, suffused in light, and in silence.