Mirror: A Tale of Twin Cities (traditional Chinese: 鏡·雙城; simplified Chinese: 镜·双城; pinyin: Jìng·Shuāng Chéng) is a 2022 Chinese streaming television series adapted from the Chinese fantasy novel Mirror: Twin Cities written by Cang Yue. The series was directed by Patrick Yau and starred Li Yifeng, Chen Yuqi, and Zheng Yecheng. Set in a fantasy world named Yun Huang (云荒), the story tells of young heirs from Quan Xian and Kong Sang tribes, fighting for the freedom of their people. The series began airing on Tencent Video and Youku from January 16, 2022. A prequel series, The Longest Promise, premiered on July 2, 2023.

In a fantasy world called Yun Huang, there exist three tribes Quan Xian, Kong Sang, and Cang Liu. A century ago, the Cang Liu started a conspiracy and seized the empire created by Kong Sang. At the battle field, Kong Sang prince Zhen Lan fought against Cang Liu until him the last one. His power of Emperor was then sealed by Cang Liu. The six young kings of Kong Sang, including princess Bai Ying, sealed all their tribal people under the Mirror Lake in order to protect them from being massacred. After a century, the young heir Su Mo from Quan Xian allied with Kong Sang and fought together against the Cang Liu Empire. After overcoming a number of difficulties, Su Mo gained the power of Dragon God, and Zhen Lan unsealed his power of Emperor. They finally defeated the Cang Liu Empire and turned Yun Huang into a peaceful world.