Out of all the authors contributing in the marathon The Horus heresy novel series, Graham McNeill has made highly significant contributions. Mechanicum is the chapter 9 of The Horus heresy novel series. The novel and the subject series is a contemporary science fiction genre, where all the chapters have got top level content and performances for the literary book lovers. Toby Longworth has done the narration of this novel and with all his prior experience and great skills with his voice and tone, he managed to pull off a great performance in this novel.
Just as the flames of the treachery of Horus gets spread right through the Imperium, Horus endeavors to destroy or subvert all those people, who dare to stand totally against him.
On Mars is the very home of the priesthood of Mechanicum, the best manufactory cities have formed a good number of the weaponry required and that too for all the expeditionary fleets that exist all across the galaxy. All this potentially makes this world invaluable and extremely precious to whoever gets hold of it in the next coming war.
At this point, the Warmaster men start to stoke the rebellion fires and that turned the loyalist armed forces and the Titan Legions in a position that is opposing one another. Then, the Dark Mechanicum come alive.
Fulgrim and A Thousand Sons novels are beautifully written by Graham McNeill. They are widely read and highly regarded as per the many feedbacks and reviews received for these recommended novels. Considering all this positive response, it would be a great idea for you to invest some time in listening to the audio narration of these novels.