He remembered a man and woman, shouting, screaming, and crying; begging him to hide a baby below decks.
An oath taken.
Running through corridors with a wailing baby as explosions and the sounds of fighting echo around them. Softly he laid said baby inside his crib and he gently wiped the tears from the baby's face and tried to reassure the child, when suddenly there was a burning sensation, more painful than anything he'd ever felt. Glancing down at his hands he realised that he'd turned the baby's shed tears into a long, crystalline dagger.
He knows what he must do…
The baby stared up at him, with the saddest look he'd ever seen on a child's face. Soothingly he ran his fingers through the baby's silken blonde hair and whispered "Remember me in dreams." He said as the baby sadly waved him off as he ran away to face the captain of the pirates attacking them.
Dagger in belt, he ran back through the corridors and up onto the deck. Only to come face to face with the villain himself.
Pitch Black, The Nightmare King.
They made eye contact across the deck and with a battle cry he launched himself at Pitch, ramming the dagger to the hilt into his heart.
He barely had time to free himself from the dagger before Pitch toppled overboard, falling through the sky towards Earth. In reality this only took a few seconds, but in those seconds that had passed, the fall felt like an eternity.
He tries to free himself only to realise that body had begun to shape shift itself smaller.
His body began to burn. He didn't know what was happening, why his powers were working against him, the feeling of his shifting body getting smaller and the Unknown left him feeling like his chest was slowly being crushed and his insides were being strangled.
His bones clicked painfully against each other as his torso shrunk, his intestines wrenched painfully and his body reformed itself in fire as each nanosecond forced him to grow smaller.
He felt suffocated, and he began to feel something that he'd barely felt before, but had witnessed many times before- fear.
Fear for his friends, fear for the baby, fear for himself. What Pitch might do to him now that he was shrinking, and growing powerless. He didn't like this, he didn't like it one bit. A strangled noise, sounding much like the squeal of tearing metal, escaped him. There was a sudden internal yanking motion as he was pulled into the dagger itself.
Jack Frost woke up screaming.