1980, United States. Llew Jones, a young Welshman in his twenties, wants to see the United States and write the novel of his life. Recently settled in his aunt’s home in the Catskill Mountains, he spends his time strolling, smoking grass and reading. One fine morning, while he is immersed in his reading by a riverside, a strange man approaches him. Joe Bosco is a butterfly seller, as charismatic as he is exasperating, who offers to accompany him across the country to develop his business of rare specimens. Then begins an extraordinary journey which ends up however escaping their control, the day Joe disappears. Llew ends up in prison and has only one chance to get out of it: convince everyone that his version of the facts is the right one.