The diary of Psyidolon Piscae tells a tale of self discovery and eventual disassociation from the gestalt of the Elder Brain.
It contains notes about his escape, and his career of research into the mixing of psionic and magical technology. These notes are in a general story like form and do not contain specifics, but could theoretically be used to start someone down a similar path of self-discovery.
It also contains local information and general history for several realms and worlds within the local area.
The latter portions discuss theoretical application of power, the uses of entropy and radiance, and somewhat disturbingly, vague notations on how to destroy or darken a sun. Notes which hint that if successful, could be used to self propagate an area of annihilated and darkened stars.