The sixth title (Scholastic, 2008) in Garth Nix's series begins with Arthur Penhaligon's asthma attack that results in his being taken to the Lower House, which is the center of all Universes. He is then declared Heir to the Kingdom and must wrest the Keys to the Kingdom from the Architect's appointed Trustees who are no longer loyal. Arthur has successfully defeated five of the Trustees, gaining dominion over all of the Lower House, the Far Reaches, the Border Sea, the Great Maze, and the Middle House. In doing so, he has become more Denizen than human and fears that he will never be able to go home upon completing his destined path in the House. Arthur is faced with simultaneous attacks in both the House and his own world, as Superior Saturday schemes to defeat him and become Denizen of all Universes. His home is beset by a nuclear attack while the Lower House is destroyed by a giant wave of Nothing. Arthur mounts an attack to take the Upper House from Superior Saturday. The novel ends with a real cliffhanger. Allan Corduner gives all the characters distinct voices. Listeners will be enthralled and eagerly await the final volume in the series. A good addition to school and public library collections.-Jessica Miller, New Britain Public Library, CT