Jareth's control snapped as the Sarah turned the knife on herself, his magic burst from him, the swirling darkness filled through the room until it filled every crevice, every crack in its walls. He was only vaguely aware of Jack's arrival, the crown prince had entered just as Sarah had spoken her last words. When Jareth's magic reached out, he used his own to keep the dark smoke from touching Sarah. He formed a whirlwind around her and forced his way through the suffocating fog until he reached her. He lowered himself over her form and breathed ice into her, freezing her heart before it could beat its last thump. He kept the whirlwind around himself, desperately trying to keep the smoke at bay. He needed to survive Jareth's onslaught of magic.

Kai's screams were piercing, Jareth's magic sought her out, all of his rage and desperation poured into her. The smoke invaded her mouth, her nose, her eyes, any way it could infiltrate her it did. It filled her, turning her blood to onyx, her skin to smooth black granite, and still Jareth pushed. He felt his power ebb, but didn't relent, he poured everything he had into her until her lungs turned to ash, her organs disintegrated. Jareth vaporized her from the inside out. Only when her ashes separated and she disappeared into the fog, did Jareth let up. He pulled his magic back into himself and felt his legs give out. He fell to his knees and bellowed, a heart wrenching sound that made the very foundation of the castle quake.

Jack released his own magic and the whirlwind eased into a light breeze before disappearing entirely. Sarah, her frozen body was face down, one hand reaching towards Jareth. Jack had seen in Sarah's eyes everything she'd been trying to convey to Jareth. She loved the Goblin King. Jack knew that now, and though it felt like his chest had been hallowed out, he would save her. Her skin was blue and ice crystals clung to her hair, to her eyelashes. She was still beautiful but it was a cold beauty, and it broke Jack's heart.

"She's not dead," Jack whispered, knowing Jareth would hear the words, "I froze her heart before it stopped." Jareth jerked as Jack's words reached him, he felt as though the prince had struck him. He forced himself to his feet and moved to Sarah's side. He avoided the blood puddle, all of Sarah's precious life force was spilled at his feet and he scarcely believed Jack's words.

"She may not be dead, but she is lost," Jareth murmured, he dropped to her side, but couldn't bring himself to touch her frozen skin. If he could take it all back, he would. He had put Sarah in Kai's crosshairs and had been arrogant, believing himself, and her, to be untouchable. Why hadn't he just let Sarah go? After she had left the Underground, he should have forgotten about her. But she had crawled under his skin and made a home for herself in his chest, right inside his heart. Still if he'd left her alone, Kai wouldn't have been able to reach her and Sarah would be alive. Out in the world and content to believe he had never existed. But he hadn't been able to, and now he would give anything for her to live, even if it meant she was free of him.

"I can save her." Jack announced and Jareth exhaled a ragged breath.

"No," he argued, "you can't. You are the Crown Prince of the Northern Summits, but turning time is out of your reach," he paused, "just as it is out of mine." Jareth steeled himself and reached forward, he softly brushed Sarah's cheek and her icy skin burned his fingertips.

"I can give her my humanity." Jack stated softly and Jareth jerked, and turned to him sharply.

"No, you cannot. To give up your humanity is a fate worse than death, it would destroy you. It would freeze your heart," Jareth said bitterly.

"Haven't you heard, my lord," Jack whispered sadly, "my heart is already frozen."

Jack pulled all of his magic into himself searching for the only thing that the Fey shared with human beings. His skin began to glow and Jareth stopped him with a hand on his arm.

"Let me…" Jareth started but Jack shook his head.

"Sarah loves you, Goblin King, if you gave her your humanity and she returned to life, I would be an unfit consolation prize." Jack extracted his arm from Jareth's grasp and his skin began to glow anew. Jareth cast his eyes to Sarah's body and knew that he would let Jack make this sacrifice, for he was not strong enough to let his precious Sarah go.

Jack directed his humanity into a metaphysical ball in his chest. He extracted the ball until it was but a glowing orb in his hands, with one last look at Jareth, he lowered himself to Sarah's side. His knees soaked in her blood and he repressed a shiver. He took the ball and pressed it into Sarah's chest, while thawing her heart at the same moment, he willed it to beat, and forced his humanity, a part of his very soul into her lungs, her skin, her blood, her own soul. As it took hold of her, her body thrashed, trying to fight off his unfamiliar soul from her body, but he was unrelenting and eventually she went still as her soul absorbed the humanity of Jack Frost.

Jack stood quickly and gave Jareth a wild look. Already he could feel the cold seeping into his heart, but he held himself there for a few more moments, waiting to see her chest raise as she took in a shallow breath. Satisfied that she would live, Jack forced himself away, leaving Sarah alone with the man she truly loved.

Jareth thrilled at the sight of Sarah's chest rising, he worried only briefly at the puff of air that was visible in the air as she breathed. She'd absorbed Jack's humanity, cold breath was sure to prove a small side effect compared to what this would truly do to the mortal. He didn't worry about that now. Sarah was alive, they would figure out the rest later. He gathered her still form into his arms and conjured a portal out of Jack's castle, he stepped through, into his own home, with the mortal he loved, his precious Sarah.