A century before the events of “Game of Thrones,” two unlikely heroes wander Westeros. In an adaption of George R. R. Martin’s novella “The Hedge Knight,” a young and naive but courageous knight, Ser Duncan the Tall, and his diminutive squire, Egg, face a series of dangerous exploits. Set in an age when the Targaryen line still holds the Iron Throne and images of the last dragon have not yet passed from living memory, great destinies and powerful foes await these improbable and incomparable friends.