Yan Qingyu, a small antique shop owner, accidentally inherited his grandmother's "Tea Book" and discovered that he could summon the little demon from the Book of Mountains and Seas through the scent of tea. When she meets Yun Shoubai, a firefighter who always comes to ask for tea, the two are gradually involved in the balance of demons and spirits in modern cities - it turns out that some "intangible cultural heritage" contains real ancient contracts.
