Note: My first try in FanFiction. A little spoiler, so they say. Jack had always been Jack ever since he became the spirit of winter, but I'd like to call him "Thomas" first when he was still human. I do not own Rise of the Guardians.
Jackson Thomas Burgess woke up, his brown eyes blinking in confusion, his brown hair ruffled from what he seemed was his bed. He last remembered his sister screaming for help in the middle of the frozen pond – a stick was in his hand which he used to pull her out of danger with all his might – but then he saw himself breaking through the ice beneath his feet. Apparently, he was forgetting something else. Where was he exactly at that moment?
He realized he wasn't in their little cottage after all. There was nobody in the surroundings, and this gave him a sense of fear. A tinge of burning sensation was stirring his insides and then radiating out of his skin. Words have failed him when a scream tried to escape from his lips but only a bubble came out of his mouth. And that was when he knew where he was.
He was under the pond.
The moonlight was shining in the dark of the night, but his vision was obscured by the thick ice separating him and the celestial orb. His frostbitten hands clawed the surface beneath the frozen sheet, but his case was hopeless. A few more minutes and he would have been out of breath. He stopped struggling and waited for his eminent death, a death that would bite him so suddenly he wouldn't realize it's done.
But it did not come.
The glow of the moonlight got brighter and brighter until he was blinded by the sudden beam of moonlight that struck him, breaking the ice that was between them. It was a spark of hope that might have warmed his very soul. But he couldn't move anymore; his whole body had frozen to death.
He didn't see that a man that seemed as ageless as time was walking towards him. This particular man had a strange glow that was enveloping his whole figure, as if he had just come out of the moon, and he did, for in fact this was the Man in the Moon. He spoke with such reverence and wisdom that Jack could only faintly hear the echo in the old man's voice.
"Wake up, my child, for you are chosen to become the Winter Spirit."
Thomas' body, his villager's clothes and all, was encapsulated by an unusual harsh breeze of the winter. His hair had turned white like the snowflakes that draped on his skin, and his eyes had opened, revealing a pair of icy blue orbs. He was alive once again, not knowing how it had exactly happened, but not caring anymore. All he knew was that he had another chance of life, his name tasting so good in his lips, as it had been given to him by the good old Man.
He breathed life once again as he was lifted out, away from the place where he died and was reborn. Jack Frost does not have a past at that moment, but he has a future that he needs to make.