Maggie (Greta Gerwig), who hasn't had much luck with long term relationships, wants to have a child. She decides that artificial insemination is the best option but no sooner has she begun the process than John (Ethan Hawke) enters her life.
John, an academic, is unhappily married to Danish critical theorist Georgette Norgaard (Julianne Moore) and Maggie is the change he's been searching for. He leaves Georgette and starts a life with Maggie.
Maggie has what she wanted - a daughter and John - but she isn't happy. As a result, she rethinks her plan and concocts a new one involving John and his ex-wife Georgette.