From a multiple Hugo Award winner: Four more novels in a brilliantly imaginative series.   In the second half of the World of Tiers series, Kickaha embarks on a journey to the eternally shifting landscape of the Lavalite World of Lord Urthona--and the ultimate clash with his arch nemesis.   On Earth, Kickaha and the Lord Anana pursue a rogue Beller called Thabuuz. They thought they had wiped out the last of the biolab-generated artificial intelligences created by the Lords, but it seems one has escaped through a portal to Southern California. Thabuuz must be found before he can spawn more Bellers and revive their war against the Lords. But even though he came from Earth fifty years ago, Kickaha no longer recognizes his former home, now ruled by a hostile Lord known as the Red Orc.   Leaving an unwelcoming Earth, Kickaha is trapped on the strange planet he thinks of as Lavalite World, and the only way out is a single gate, located inside Urthona's palace. But the stronghold moves as readily as the dangerous terrain, making survival an unlikely prospect.   After facing harrowing challenges and finally returning home to the World of Tiers, Kickaha is led into one last trap. He'll have to confront the fearsome enemy who has been hunting him all along--and the fate of the pocket universes lies in the balance.   This omnibus contains the author's preferred text of the novels Behind the Walls of Terra and Lavalite World, reprinted from the limited edition volumes published by Phantasia Press.