Xiang Shaolong (Louis Koo), a member of the 21st century special forces, is determined to participate in the research of time travel in order to save his love. However, due to the data error of the time machine, Shaolong was brought to the Warring States Period. At that time, Ying Zheng (Raymond Lam) had not yet ascended to the throne and was imprisoned in the State of Zhao. In order to return to the future, Shaolong did everything he could to help Ying Zheng ascend to the throne. Due to Shaolong's extraordinary wit and special identity, his ability was appreciated by everyone, so he was also plotted against by many cunning people. Under the circumstance of being attacked from all sides, the romantic Shaolong was also entangled in a complicated four-corner love relationship. Can Shaolong help Ying Zheng win the world? How will he deal with his relationship with his lover from another world?