十九岁那年，沈星（易烊千玺 饰）骑着小摩托穿越边境漫长的花海，误入一片荒蛮之地。他像当地人一样抹上蓝泥抵御着无处不在的花粉，也在这时真时幻的花粉中，经历着一个个斑斓、狂野而离奇的故事。

折耳与美短，理想与现实，亲情的羁绊比海更深。

A young lady comes to Lhasa alone for pilgrimage, but a "multicolored magical lobster" enshrined by other people has totally changed her plan. She made a decision to take the lobster home to the ocean, and this set her and the lobster on the journey cross half of China. During her journey, she comes cross many interesting characters and experiences. At the same time, memories, dreams, and hallucinations emerged intermittently. The journey to set the lobster free came to an end in an unexpected way. She finally reached the most secret place in her heart.