They say that people who in their seventies would have told 90,000 lies throughout their lifetime. Dai Meng, Liao Duo Duo, and Hua Sheng are three individuals who use lies as a means to seek out the truth.

Expert lie detector Dai Meng resigns from his job due to a mistake at work. He opens up a firm that specializes in solving all kinds of problems from emotional disputes, debts to work-related issues. As long as it does not violate the law, he will accept any job.

Dai Meng relies on his expertise in analyzing the telltale signs of a lie to help him in his work. With business booming, he crosses paths with Liao Duo Duo, a fellow analyst, and they immediately have a go to see who's better. Dai Meng wins the round but gets stuck with her company.

Dai Meng, Liao Duo Duo, and their assistant Hua Sheng form a three-person team. As requests come in, they help their clients expose lies to make way for the truth. When Dai Meng discovers that the people closest to him may have ulterior motives, he realizes that it all leads back to the reason he had to leave his job in the first place. Dai Meng restarts his investigations to find out the truth once and for all.