When we meet Calvin (Paul Dano), he's wallowing in a sophomore slump. Having been thrust into the limelight by the success of his first novel, he now finds himself unable to follow his own opening act. Calvin spends days of writer's block wandering the airy, sterile apartment in which his small dog offers the only consistent company. Occasional visits from his married brother, run-ins with fawning fans, impatient agents, and obligatory book signings all conspire to undermine his creative spirit.

Inspiration finally strikes, however, in the form of a recurring dream. Ruby Sparks, as he names the subject of his nightly fantasies, soon becomes the subject of Calvin's writing as well. After he's spent weeks obsessively typing out the minutiae of her character, she manifests herself in his living room, insisting that she's his girlfriend. Perhaps he's lost his mind or perhaps he's experienced a miracle, but after Ruby's existence is confirmed by a third party, Calvin is fairly content to enjoy his circumstances without further questioning.

Though Calvin can dictate every detail of Ruby's being with a stroke of his quirkily anachronistic typewriter, the film generally relegates this detail to the background. Fantasy elements are invoked economically, but Ruby's magical existence serves less as an ongoing magic show than as a vehicle for exploring the nature of happiness within the context of romantic relationships. We watch Calvin and Ruby settle into the malaise that real relationships invariably face, and we're prompted to wonder how long happiness can last in any situation, even a literal dream come true, before it yields to ever-creeping discontent.

Dano, a gangly, slouching, boyish figure who generally looks like he's either entering or exiting a sneeze, is well cast and easily embodies the bookish, self-effacing Calvin. His performance is engaging enough to carry the film through weaker moments, such as a weekend trip to Big Sur to visit Calvin's caricatured new age mother (Annette Bening) and her equally outlandish chainsaw-artist boyfriend (Antonio Banderas). Primo bit parts from Steve Coogan as Calvin's slimy agent and Elliott Gould as his shrink are both fitting additions, and perhaps the most interesting casting decision is Zoe Kazan, who not only plays Ruby but is also the film's screenwriter. Kazan's performance as the powerless, objectified creation of Calvin's imagination gains added depth when we remember that she is the ultimate architect of the story, the writer writing the writer who writes her. Dano may be the star of the show, but it's Kazan's dual performance that make this film an effective and moving critique of relationships and the stories we tell ourselves about them. recommended