From publisher blurb:
A field of magical energy envelops Urth and spreads out across the cosmos. A residual force left from the act of creation that brought this reality into being, this energy is the cause of nearly all the strangeness found in the world: from the bizarre monsters spawned within the foul slicks pooling in caves deep under Blötland to the hidden kingdoms of the faeries; it is responsible for the floating lands above the Desolation and countless other oddities one encounters when traveling the lands of Rûl and beyond.
This energy has even been harnessed and channeled into the creation of artifacts and relics of wondrous and terrible power. More common, however, than all of these supernatural phenomena and wonders are spells: magical effects discovered, codified, and devised by those people who make a study of magic in its many forms. From the destruction of the fireball spell to the awful glory of hateful defecation, spells offer staggering power to those individuals with the patience, cunning, and will to learn them.
The Paths of Shadows series expands and updates certain paths from Shadow of the Demon Lord to create new variations and possibilities. Paths of Power deals with the sorcerer, spellbinder, warlock, and wizard, and in most cases offers upgrades and enhancements to make them even more exciting to play. In addition, this supplement introduces a new path: the occultist, a dreaded devotee of dark magic, who peers into places others fear to look.