"Forbidden Empire" takes place in 15th-century China, during the early Ming dynasty. The story revolves around Thomas (James Purefoy), a British adventurer who becomes embroiled in the intrigue of the imperial court. Alongside his trusted friend and warrior, Chen (Jing Lu), Thomas must navigate the treacherous waters of royal politics, eunuchs, and ancient traditions. As they embark on a perilous journey, they discover a mysterious, powerful artifact that could change the course of history.