Calvin Weir-Fields (Paul Dano) is a Los Angeles wunderkind who wrote a seminal novel at the tender age of 19 but now, at 29, can't quite produce his sophomore masterpiece. Then he wakes from a dream pulsing with creativity and an obsession with the girl he found in it, a pretty and maddeningly charming painter named Ruby (Zoe Kazan). At the urging of his shrink (Elliott Gould), Calvin writes about Ruby until, without explanation, he has, as his brother (Chris Messina) points out, "manifested" her. Ruby appears in Calvin's kitchen, an amazing girlfriend at the ready. Calvin discovers he can control Zoe by simply writing her, but is that what he wants? And is that what's best for Zoe?