Alice is a sailor. While her partner Félix waits for her on land, she sets off as second mechanic on the Fidelio, an old freighter. On board, she discovers not only that her predecessor has just died, but also that the skipper is none other than the first great love of her life. Alice finds a notebook in her cabin, apparently that of the former mechanic, and on reading its contents – accounts of mechanical problems, sexual conquests and lovelorn emotions – finds, oddly, that they mirror her own concerns. As they make stops at various ports, dealing with life aboard alongside an all-male crew and the swell and pitch of her romantic feelings, the young woman tries to stay on course.