In order to raise money for his father, San Qing went undercover to a hotel called Laifu Hotel near the hospital, trying to disturb the business of the hotel, thus forcing the owner Xiao Lin to agree to demolition. But in getting along day and night, San Qing not only develops friendship with the members of the hotel, but also witnesses the life stories of the guests in the hotel. He struggled constantly in his heart, and the originally simple undercover mission became his choice of dignity.