The story begins in the year 2000 at the Ohara Museum of Art in Kurashiki, known for its impressive collection of modern paintings. Security staff member Orie Hayakawa receives an unusual request: with the cultural activities director of a major newspaper company at his side, museum director Takarao asks her to go on an overseas assignment. The newspaper is putting together a major retrospective on Henri Rousseau that will tour Japan, and when they approached the Museum of Modern Art in New York for a loan of the artist's Le Rêve (The Dream), chief curator Tim Brown requested that Hayakawa be placed in charge of the negotiations. Having earned a doctorate from the Sorbonne at age 26, Hayakawa was once a rising star in the art history world as a Rousseau specialist, but abandoned her research following a certain incident. She is?now the single mother of a 16-year-old daughter.
In Chapter Two the story shifts back to the week in August 1983 when Hayakawa and Brown first met. The two had been invited by a legendary art collector to his mansion in Basel, Switzerland, to help determine the authenticity of a work in his collection attributed to Rousseau and called I Dreamt. The work closely resembles Le Rêve, but the possibility has come to light that a work by Picasso from his blue period might be hidden beneath it . . . The reader is drawn into an intricate, white-knuckle mystery centering on the provenance of the painting.