Freshly single Don Johnston (Bill Murray) receives a letter informing him that he has a son who may be searching for him; the sender remains anonymous. With the help of his friend Winston (Jeffrey Wright) he sets out on a road trip to revisit his old flames and discover clues as to who the mother might be. Don finds his exes in all walks of life, and the encounters range from sexual to awkward to plain violent. As the movie continues, Don not only revisits his ex-girlfriends, but also his own past and leads him to re-appraise the life he is leading.