The Athenaean Scrolls are an artefact of the Thousand Sons.
The arch-sorcerer Ahriman consumed the knowledge contained in the Athenaeum of Kallimakus long ago. However, not all of the Athenaeum’s founders were slain when their repository of knowledge was destroyed. Some of their Apollonian disciplines have since been transcribed on sanctified papyrus in order to keep an echo of that great library in existence. One who possesses the so-called ‘Athenaean Scrolls’ has access to advanced psychic techniques that make his spells all but unstoppable.