On the winter solstice, Yang Yuan’s son vanishes after sneaking into a neighbor's house. Meanwhile, Yuan Wu deals with his father’s sudden death, and Lin Chu Ping experiences a frightening incident with no memory of the attacker. These seemingly unrelated events begin to connect as the characters search for answers.

执掌风霖的东海龙女（李沁谣饰）因失去记忆，化成一条鱼，意外遇到和自己有宿世因缘的韩湘子（张远饰），二人受说书人的点化，一路向东历练寻找龙门。 在帮助龙女“跃龙门”的奇幻之旅中，韩湘子也逐渐领悟了爱的真谛和人间大义，千年东游不负深情。

影片以一座“没有人心，只有规矩”的人间隐市做背景，隐市规矩自成一体，从而形成了一个全新的生存世界及世界观。全片涵盖了“奇谈”、“悬疑”“药理”等多重元素，围绕 “天赋医师”白青萝（郜思雯饰）同“诡案捕快”拾生（蔡佩池饰）的破案经历，揭开了一件件跌宕起伏扣人心弦的悬案谜底，巧思设置既环环相扣又能发人深省。