Jack didn't mean to be kidnapped, it just sort of happened. After the fight with Pitch he just needed some time to think. To be honest, Pitch and his dark sand scared him. He'd never admit this to the other guardians, his tough guy, couldn't care-less bravado would go right out the window and be trampled by North's reindeer. Jack just needed some time alone to get his act together. Jack was an expert on alone, he wasn't used to being around others who could see and interact with him. He'd come back and help them out, honest.
Jack meandered through the streets without a real destination in mind. After all, he usually went where the wind took him. But strangely, there was no wind tonight. That was what woke jack out of his pensive state. There was always wind where Jack went, he'd never seen a still day as long as he could remember. Jack looked around as he gripped his staff. He'd somehow cornered himself in a dead-end alley, facing a tall brick wall covered in graffiti with no way over. Jack turned around and saw a tall nightmare pawing the ground. Jack blasted it with a gust of frigid winter air, but the horse danced out of the way as it neighed into the dark sky. It was a signal.
"Hello Jack," a sinister, familiar voice said. Jack turned again as Pitch literally stepped out of a shadow on a wall. "We need to talk."
Pitch had sent out his nightmares all across the world with one goal, 'Find Jack Frost.'
The boy had sparked his interest over the years, but now, with Pitch's plan in full swing, the boy was needed. Jack had much to offer with his particular set of gifts. All he needed was an incentive. Insanity was always a good one, and it was oh so easy to unlock. Insanity, as you know, is just like gravity, all it needs is a little push. Pitch found the boy around midnight. He stepped out of the shadows to draw the boy's attention away from the nightmare. " Hello Jack," he said. "we need to talk." The boy's eyes widened and he pointed his pesky staff at Pitch. As far as Pitch could tell, the staff channeled Jack's power, but the raw force of winter was in the boy himself.
"What do you want?" the boy demanded, eyes narrowing in distrust. Pitch couldn't help but smile, "Why Jack, I only want the same as you, I suppose. Acknowledgment, admiration, respect, a purpose."
"I'm nothing like you."
"you misunderstand me. I just want to be recognized by the people of the world. To be believed in." The boy lowered his staff, he knew the feeling well. Then he pointed it again at Pitch, "You want to rule the world through fear, I'll never help you." the staff started to glow a chilly blue, but Pitch beat him to the punch. The nightmare crept up behind the boy and reared. Its hooves lashed out and struck him in the head. His eyes rolled into his head and he fell to the ground. Pitch leaned over and took the staff, which was no longer laced with ice. "Never say never, boy." Pitch nodded to the nightmare which swirled around the two still figures. A moment later there was a flash and the sand settled. Pitch and Jack were gone.