In the final volume of Hamilton's thoughtful but disappointing "Justice" trilogy, the four psychic children once more form the "first unit" and travel through the Crossover to the desolate future Dustland. There they help some of Dustland's inhabitants, who have been exiled by the dread presence Mal, to escape back to a domed city in "domity," run by creatures who are part human, part machine. Among those who escape from Dustland are the humanlike three-legged Slakers and the doglike Miacus, both met before, and a new group of primitive, wandering young humans who travel in a "packen" of 15, divided into five "trips," each containing a leader, Duster, a "leggen," Siv, and a "smooth-keep," Glass. (The "youngens" in the other four trips are mere duplicates of the lead group.) As the children in the Unit "trace" to communicate, those in Dustland and domity "tone," and Justice now enters the master machine Colossus to absorb knowledge of the post-disaster society and its history. She learns too the Unit's role in the Grand Design: as Levy and Thomas are "twinned," so too is Justice. The mission of the Unit is to leave the Watcher in Justice behind; and as it splits from her the four children return to the present, to stay safe and normal until their power once more wells up and finds a mission. By the end of the third volume, then, Hamilton has established a future world as the children find it, complete with a range of mutant and created creatures, philosophical challenges, and the alternative revolutionary and social arrangements so dear to future fantasy creators. But that is where we might expect to be at the end of volume one, and we arrive there through expository conversation. We never see the four childrens' powers satisfactorily fulfilled, or see the time their formation as the "first unit" foretold. We never actually see any crisis or confrontation in the tightly controlled domity; and we never actually see the questions raised by the society's Master Plan played out in action.