The books listed so far will explore a number of possible theories surrounding the Heresy, focusing either upon key single events such as the loyalists successfully holding Mars to key figures completely reshaping the story. The first in this series is set to examine the idea of Nathaniel Garro turning traitor with the rest of his legion and robbing the Imperium of an early warning, and will directly involve the missing primarchs. Many ambitious stories will follow other possibilities, most notably a rather tasty concept involving the Emperor allying himself with the Chaos Gods, ascending with them and forcing the majority of the Malcador led primarchs to halt his mad rampage. Others hinted involve Ulthwe directly intervening during the Battle of Terra, and a time travelling expedition of the Tau Empire appearing during the Battle at the Phall System.
Unveiling their road-map for the next hundred releases, Forge World accidentally let slip the finale to this entire gambit, where each time-line would eventually coalesce into a single event. Titled Crisis of Infinite Heresies, the story will introduce the corrupted spirit of Ferrus Manus and his attempts to annihilate all of time and space. Now surgically fixed onto Vulkan's body and naming himself Ferrus Caput, he seeks to end everything and start over with himself as the new Emperor, erasing all prior Imperfections in the canon. The book will see the creation of the League of Extraordinary Lokens and the all powerful Ultramarine Corps led by the Guillimans of the Universe. This will then lead into the event Zero Terra, during which an enraged and super-powered Cato Sicarius will seek to punch the walls of the Warp.
Further individual books are planned for the xenos species, devoting entire volumes to one faction after another; ideas will range from the Tyranid Hive Fleets consuming all of the Sisters of Battle and promptly becoming devout servants of the God-Emperor to the Dark Elder entering rehab en mass. As ever though, the core stories will focus exclusively upon the Imperium of Man.
Expect further news as this story develops.