Long, slow, fascinating... This is NOT the book to read if you're looking for a slambang blasters & space battles SF story. It's very "real" sci fi, set in a near future where humans have colonized part of the solar system, and reads more like an SF version of Da Vinci Code than a typical SF story. Our heroes uncover an elaborate planet-spanning riddle in the wake of their famous aunt's death, which sets off a puzzle-solving tour of this future solar system where robots fight arena battles on Mars and modified people form nations underwater. It's relaxed and fascinating, and makes a marvelous tour of a possible future.