This fic is going to be a bit darker than the rest, but no worries, there will be smut!
"I believe in you, Jack, and I know children will too!"
"In me?"
"Yes! Look at what we can do together!" Pitch said, motioning to the pillar of darkened ice that was created from their battle.
"We can create a world where everything, everything is-"
"Pitch Black?" Jack asked, cutting Pitch off. Pitch paused for a second before giving a crooked smile.
"And Jack Frost, too." He said, trying to reassure the frost sprite.
"They'll believe in both of us!" Pitch said excitedly, but Jack scowled at the Nightmare King.
"No, they'll fear both of us, and that's not what I want." He retorted, turning away and taking a few steps.
"Now for the last time, leave me alone." He growled, but suddenly stopped and
gasped as Pitch appeared in front of him, grabbing him by the throat, and shoving him against the ice pillar. Jack was gasping for air, looking up and seeing that Pitch's eyes were narrowed, and he glared into Jack's eyes, hatred and malice clear in the golden orbs, making the sprite shiver with fear.
"You want to be left alone? Fine!" Pitch snarled, pulling Jack into the darkness with him. They emerged in one of the empty cages that hung from the roof of Pitch's lair, and Jack fell back against the bars, gasping for air as his throat was released. He watched helplessly as Pitch left the cage with his staff, snapping it over his knee.
"No!" He screamed, clutching his chest, feeling a pain as if Pitch had cut him open. A sick look of satisfaction came across the Nightmare King's face as he watched Jack fall to his knees and pass out. The chirping of the mini tooth fairies had been loud as the two arrived, but was now deathly silent as Pitch locked Jack's cage and threw the broken staff to the side.
"Then be alone." Pitch growled, returning above ground to finish what he had started.
Jack woke up a few minutes later, groaning in pain. His head spun and his soul felt broken, much like his staff. He reached in his hoodie pocket and pulled out his memory case, scowling at it.
"Pitch was right, I do make a mess wherever I go." He whispered to himself, letting the golden case slip through the bars of the cage, and crash to the floor, earning him scolding sounds from the fairies. He sighed and pulled his hood on, turning his back to them. He looked over to the globe that Pitch had, watching as the last six lights began to go out, until only one was left.
"Jamie!" Jack said, knowing that Jamie's belief could turn the battle around. His mind wandered to the brunette, and he smiled.
"If anyone can help the Guardians, it's you, Jamie." He said, his words echoing in the dark cavern.
Jack had dosed off, and woke to find Jamie's light on the globe was dimming, getting darker and darker, until it finally went out with a hiss. Jack let out a broken sob, and he heard his frozen tears hit the bottom of the metal cage with small tinging sounds; tears he hadn't realized slipped down his cheeks.
"Jamie, I'm sorry. This is all my fault." Jack whispered, closing his eyes and sobbing silently. Suddenly, Pitch's laughter reverberated around the cavern, accompanied by snorts and whinnies of his Nightmares.
"There is nothing left, Jack! Nothing left but fear!" Pitch said, emerging from the shadows and sitting on a large black and gold throne.
"Your precious Guardian friends-"
"What happened to them!?" Jack snarled suddenly, his anger overcoming the sadness.
"Nothing! They are just weak and useless. Unable to do their jobs, and without anyone to believe, they will stay that way." Pitch said, looking quite proud.
"If I had my way, I'd kill them, but the Man in the Moon has granted them all immortality." He added in a growl.
"And you, dear Jack, you have already died. Unfortunately for me, MiM has given you another eternal life, and I'm afraid you cannot be killed either." He said, and Jack glared at him, pure hatred in his eyes. Thousands of Nightmares streamed into the cavern and took the children's memories and brought them away, most likely to be destroyed. Some of them gathered the fairies in their cage like bellies, and galloped off, leaving the cavern silent.
"Don't look so scared, Frost." Pitch said.
"They are going back to Toothiana, as I have no use for them. Even reunited, they will be powerless, none of them are able to fly." He said, smirking.
"You should've seen it! Little Jamie Bennett, he fought so hard with the Guardians, but the fear was too much. He lost them in the darkness, then found himself utterly alone." Pitch said, knowing that Jack was being torn apart.
"The way he just gave up on them." Pitch sneered, standing and making sand stairs to stand next to the cage.
"Stop!" Jack snarled, launching himself at Pitch, anger giving him strength. Without his staff he was mostly powerless, but he still had a little bit of control. Pitch caught his wrist and bared his teeth at the trapped sprite. The temperature dropped and the winds picked up, matching Jack's rage, surprising them both, though Jack didn't show it. Frost began to climb up the bar he was gripping with his other hand, and it spread beneath his feet.
"When I get out of here, Pitch, you're dead, immortal or not." Jack hissed, focusing the frost to his wrist, making Pitch let go.
"If you can get out." Pitch snarled, shadow tendrils wrapping around Jack's wrists and tying them behind his back. Pitch grabbed his throat again and sneered.
"And if you can stop the change." He said darkly, his suddenly claw like nails breaking Jack's skin before he let the sprite go.
"What change?" Jack rasped, gulping down air and struggling against the shadowy restraints. Pitch smirked and let sand wrap around Jack's neck, making a collar. The sand slowly began seeping into the punctures on his neck and he screamed in pain, the darkness flooding his icy veins and heading to his heart.
"A change that I plan to make slow and painful, my dear Jack." Pitch chuckled darkly.
"But you will be mine, for what goes better than cold and dark?" He added, vanishing in a cloud of nightmare sand, leaving only the echo of his laugh behind as Jack fell to the bottom of the cage, writhing and screaming in pain, his icy tears adding to the frost that was spreading over the iron bars of the cage.