As Alma Whittaker's careful studies of moss take her deeper into the mysteries of evolution, the man she comes to love draws her in the opposite direction --- into the realm of the spiritual, the divine, and the magical. Alma is a clear-minded scientist; Ambrose is a Utopian artist. But what unites this couple is a shared passion for knowing --- a desperate need to understand the workings of this world and the mechanisms behind all of life.