In this hard-boiled detective novel set in the future, Brin gleefully plays with the concepts of identity and immortality. In this future, we have figured out how clone short-lived, clay versions of ourselves, which can then go out and do the work while the originals enjoy lives of leisure. Since the copies are expendable, they are often assigned risky tasks or sent out to do chores or other drudgery. But since the copies possess all the memories and consciousness of the original, they are cursed with a knowledge of how brief their lives are, and their only fulfillment comes from making it back home to download their memories into the original, in that way achieving a kind of afterlife. Layered on top of all that is a mystery told from the points of view of a private investigator and several of his copies unraveling a complicated conspiracy case culminating in a plot by a mad scientist to achieve godhood, and this becomes a very complicated plot indeed. Good thing Brin tells it with a sense of fun and humor.