The Aldous Lexicon - called The Withern Rise Trilogy in the United States - follows the unnatural comings and goings of two teenagers, Alaric and Naia Underwood, male and female versions of the same person in alternative realities. In the first book, A Crack in the Line, Alaric and Naia become aware of one another for the first time and explore the great differences in their lives, which, until two years ago, were as alike as they themselves appear to be. In Small Eternities, hitherto unsuspected universes begin to spin around them, leading to a conclusion, in The Underwood See, which neither they nor anyone else could have anticipated.