In a last-ditch attempt to revive their relationship, writer Su Dong invites his ex-girlfriend Zhao Ying on one final trip, planning to woo her at the site of a mythical tree that blooms only once every 100 years. Zhao begrudgingly succumbs to Su’s pestering, but unbeknownst to Su, she has also invited her new fiancé, the older and seemingly dim-witted Gu. Growing increasingly jealous, Su makes Gu his unwilling rival. Between long, arduous hikes and over-the-top romantic gestures, Zhao remains unimpressed. However, an uncanny friendship forms between the two romantic rivals, until the trip takes a sinister turn that eerily mimics the plot of Su’s latest novel.