Book of the Damned
Book of Necromantic Summoning.
Three times per day as a swift action you may increase your caster level while casting a “summon undead” spell by 1.
This tanned book with what appears to be a leather cover is inscribed with the Rune of Hunger. Closer inspection reveals the “leather” to be human skin.
The Book is written by an ancient necromancer detailing the preservation of the dead for necromantic rituals. It s dark rituals lead to its banning in several nations, including Ascamae. Copies of the book are incredibly rare.