One of the most engaging elements of Game of Thrones is its hidden lore and obscure societal details. A fan could watch or read for ages, gradually lulled into a false sense of security by the grounded historical fantasy, only to be shocked by a bizarre new detail. When Arya's story about a princess escaping the monsters who killed her father suddenly becomes about a cult of assassins worshiping the Many-Faced God, the story reveals another layer of brilliance.