Ten years ago, the entire Shen family was massacred overnight, leaving only the young Shen Song alive. When Shen Song grew up, he passed the imperial examination to seek revenge, but fate played a trick on him and he was eventually demoted to a commoner. During the fire at Huamen Tower during the Empress Dowager's Thousand Years Festival, Shen Song exposed the inaction of the local prefect and thus became the emperor's "common man". During this process, he met Gongsun Li, Li Qin Er, Zhan Mao Er and others, formed a detective team to solve many bizarre cases, and finally uncovered the truth behind the extermination of the Shen family.