In the mythical, medieval land of Westeros, a civil war brews between the several noble families over rulership. Meanwhile, across the sea, the daughter of the kingdom's former controlling dynasty attempts to make her way back home and reclaim the throne with the help of her three dragons.
While the conflict of political power ensues in the civilized world, an ancient, forgotten army of an undead race located far north of any inhabited territory begins traveling south for a chilling invasion, known fearfully by the living as "winter".