On the technological, decadent world of Proton, someone was trying to destroy Stile, serf and master Gamesman. His only escape lay in Phaze, a world totally ruled by magic. Soon he learned that his alternate self had already been murdered, and that he was next. On Proton, his fate depended on winning the great Games. On Phaze, he must master magic to survive. And if he used any magic at all, his friends were determined to kill him at once!

In this brilliant continuation of the epic adventure that began in Split Infinity, Piers Anthony again proves himself a master of both fantasy and science fiction For Stile, life was a matter of shuttling madly between two worlds, with the problems growing greater on each. On the science world of Proton, he was a serf, trying to prove his right to exist by competing in the Great Games. On Phaze, where only magic worked, he was the Blue Adept, trying to master the powers of sorcery. And on both worlds, someone was trying to assassinate him. Aside from winning increasingly difficult contests with no time to prepare, all he had to do was win the love of the Lady Blue, fight a dragon, discover the ultimate weapon—and, of course, seek the paranoid Adept or the all-powerful Citizen who was trying to kill him! And now, just when things were growing impossible, he had to fight a mortal duel with the unicorn Herd Leader, against whom his magic powers were useless!

In this brilliantly satisfying conclusion to the epic adventure begun in Split Infinity and continued in Blue Adept, Piers Anthony again proves himself a consummate master of both science fiction and fantasy. Stile had problems—two whole worlds of problems, in fact. On Proton, a world of future science, his murder was averted only by the help of a lovely robot, who sent him through an invisible "curtain" to Phaze, an alternate world ruled by magic. There he found he was the double of the sorcerer, the Blue Adept, who had been mysteriously murdered. And the assassin was after Stile! To survive, Stile had to master magic, fight a dragon, win the friendship of a lady unicorn, locate his enemy among the paranoid Adepts, and return out of Phaze to win the Great Games on Proton. After that, he was ready to face the real problems! The infallible Oracle was suddenly involved in the conspiracy against him. The two worlds were out of balance and heading for disaster. Stile was somehow supposed to take over the job of saving them or go down to total destruction with all he loved, he had to act and act quickly—with no idea of what he was supposed to do.

Two worlds—the scientific Proton, and the magical Phaze—exist side-by-side. Now, Mach has crossed from Proton to Phaze, switching places with his counterpart Bane. And both must learn to survive in environments alien to their own nature.

Proton and Phaze, parallel worlds of science and magic, are ripe with the seeds of revolution. Mach, a brave and sensitive robot from Proton, and his alternate self, magical Bane from Phaze, hold the power to link the two warring systems – or destroy them entirely. Both are prepared to save their worlds. But neither Mach nor Bane had anticipated the dangers of forbidden love ... with members of the opposite realm!

The combined magic and technology between the parallel worlds of Phaze and Proton is not enough to save the planets from a conquering invasion. Only Mach and Bane—robot and wizard, linked between worlds—have any chance of stopping this threat.

With resource-rich Phaze/Proton threatened by the imperialistic Hectare and with the Adepts and Citizens incarcerated or in hiding, it falls to Nepe and Flach, two children with special powers, to save their world