Book Four of the Patternist Series.
Patternmaster is out of print.
The combined mind-force of a telepathic race, Patternist thoughts can destroy, heal, rule. For the strongest mind commands the entire Pattern and all within it. Now the son of the Patternmaster craves this ultimate power. He has murdered or enslaved every threat to his ambition — except one. In the wild, mutant-infested hills, a young apprentice must be hunted down and destroyed because he is the tyrant’s equal…and the Patternmaster’s other son.