Warhammer 40k - Horus Heresy Audio Book - Aurelian by Aaron Dembski-Bowden

After the Battle of Istvaan V, the traitor primarchs assemble to deliberate their next moves. Lorgar of Word Bearers, however, disrupts the meeting with his insinuations that Fulgrim of the Emperor's Children is not who he appears to be. His uncharacteristically confident and aggressive demeanour proving no less surprising and disruptive than his claims, the meeting is quickly adjourned by the nominal leader of the group, the Warmaster Horus.

In the aftermath, Magnus the Red of the Thousand Sons confronts Lorgar about not only his new attitude, but about his blossoming psychic powers and his knowledge of the events that have led them all to their current situation. Lorgar chooses to reveal to his brother a tale of a pivotal moment in his life; what happened when he entered the Eye of Terror some forty-three years earlier...