After losing both his parents in an accident, Jack Grey was adopted by Eric Queen who is a friend of his father. He becomes close friends with Eric's aloof granddaughter Alicia and they accidentally discover Eric's secret identity as a phantom thief. Jack persuades Eric to teach him the art of a thief, and thus the elusive thief 'Joker' was born. Join their adventure as they steal the world's greatest treasures. And slowly uncover the secrets of their past.