The power of the King of Ice and Darkness was so complete it enthralled the entirety of Winterfell for a single night. One that stretched in frozen blackness so terrible even dragon fire struggled to be seen. The terror and frost and dead things consumed the North for that time.
Under the castle the ghosts of long dead Starks rose again as thralls of the night, not as friends to their kin, but foes. They killed the defenseless inhabitants, mercilessly, turning sanctuary into slaughter.
The castle of Winterfell had turned itself from its inhabitants and was given over to the enemy. In the godswood the green seer watched it all, and remembered, seeing what was to come, even as the sons of Craster and their lord marched through the trees to the pale weir-wood where he sat, all in eerie silence. They slew his protector, the Sea Wolf, redeemed at long last.
So secure in his great victory the pale King stood and regarded his age old enemy with his unfeeling stare as behind him soared his doom ready to strike him to the true death. For in the end he was not broken by kings or queens, not from warriors of great strength and renown, not even undone by the dragon flame, but from a girl. One that had struggled and lost herself, becoming no one, and then herself again. One destined to close the eyes of many, eyes of brown, green, and blue alike. Plummeting from her high roost the girl was caught by the Night's King in his frozen iron grip and held aloft like paper on the end of a branch.
This was his hour of power for no man, woman or child was destined slay him now. No one that is but someone that was no one. In what seemed like defeat, for both the living and her, the dagger once poised to strike fell... and was caught again.
Arya Stark pierced her blade through were the foul monster of Nature's magic had birthed him saving the green-seer with the very knife meant for silencing the one it now saved. Around them the lords of winter, those same walkers that had composed their king's court shattered the same as their master, undone by the magic's breaking. The great army of death sputtered out and crumbled, their puppet strings snapped. The spell over Winterfell ceased and the dawn appeared.
The Priestess of the Red God stumbled from the death filled halls, her work completed. She at last had fulfilled her purpose as had Arya hers. Grasping from the ruby chocker around her throat, all the while shuffling out the doors. Watching the sun rise on what her fate long had been Melisandre crumpled to the ground and turned to dust, the former smuggler that had once wished her dead witnessed her relief in success, even as she died, turning to dust, the sun shining before her.