During the spring kite contest in Bianjing, after winning the championship, Ma Junqing mysteriously disappeared while carrying a handmade double-swallow kite. The child bride Haitang and official's daughter Xiuying grew suspicious of each other. Young Bao Zheng led a think tank including Gongsun Ce and Zhan Zhao to investigate. Following the blue silk thread from the damaged kite, they ferreted out the colluding Mammy Chen and the Ma family undercover Master Zhao, uncovering a conspiracy of commercial revenge behind the kidnapping. Bao Zheng set up a chalk circle trial to pierce through the entanglements of human hearts, and everyone successfully rescued Junqing, while the youths also learned that sincerity and friendship matter far more than victory or defeat.