Love Across Time: The Legend of the Yunlan Kingdom tells the wondrous transmigration journey of Lin Xiao, a young modern writer. Obsessed with ancient culture, Lin Xiao happens upon an ancient book about the mysterious Yunlan Kingdom, acquired after making its way through several countries. After touching an illustration of a bronze mirror, she transmigrates to a forest in the Yunlan Kingdom and is suspected of being a spy from another country. She is taken to the prince's residence. When questioned by the prince, she tells him the truth about her transmigration, but no one believes her, and she is locked in a dark room.
Just as Lin Xiao is about to despair, Su Yu, the prince's adopted son, recognizes the ancient book as a lost, one-of-a-kind text from the Yunlan Kingdom, and his attitude softens. Lin Xiao tells Su Yu in detail about the Yunlan Kingdom's history and culture, as well as the legend of the mysterious bronze mirror. Su Yu is astonished by the depth of her knowledge, and his suspicion gradually gives way to curiosity. After that, Lin Xiao and Su Yu investigate the secrets in the ancient book together, searching for a way to return to the modern world. Along the way, they go from strangers to close companions, joining forces to uncover the many secrets hidden in the Yunlan Kingdom. As they face hardship together, feelings quietly blossom between them, and a romantic love story spanning time and space begins. Their fates are also closely intertwined with the future of the Yunlan Kingdom, bringing plenty of uncertainty and challenges.
