From the back cover:
"Mystery Codex is a supplement for the Witchcraft roleplaying game. In it, you will find:
Two new Character Types, the Spirits and Undead, with accompanying character creation rules, powers, vulnerabilities and background for Ghosts, Phantasms, Vampyres and the Relentless Dead.
New associations: shunned Pariahs, dedicated Iscariots, elite Storm Dragons and death-obsessed Thanatoi.
New Invocations and Necromancy, the gruesome Disciplines of the Flesh, and the mystical Tao-Chi.
Background on Geburah, the Sephiroth of the Dead.
New Character Concepts, Qualities and Drawbacks, SKills and Rules."