From publisher blurb:
Secret Paths of Occult Power!
Pathfinder Roleplaying Game: Occult Adventures introduced psychic magic to the game, with five classes of psychic spellcasters, expanding the number of sources of magic from two (arcane and divine) to three. Unfortunately, certain aspects of the game that were made before the introduction of psychic magic, which could not have been predicted at the time they were made, are incompatible with this new type of magic. One such aspect was prestige classes, where prerequisites often required arcane or divine spellcasting specifically, such as with the arcane archer and the mystic theurge. While many GM's could simply rewrite the prerequisites if they chose, it seemed like the perfect opportunity to make some brand new prestige classes that specifically captured the psychic and occult flavor.
This book contains four new prestige classes for psychic spellcasters. The component artist blends arcane and psychic magic, in the style of the mystic theurge, but gains the ability to substitute one type of components for another, and gains benefits when casting spells with certain components. The dark mind infiltrator mixes physical stealth with psychic sneakiness, and specializes in warping the perceptions of their targets. The focused blade blends psychic powers and physical prowess, making powerful psychic strikes and using his blade to distract opponents from dangerous psychic assaults. Finally, the psychic intercessor finds common ground between psychic and divine magic, tapping into the will of the multiverse to invoke powerful divine interventions.