Having recovered from his grievous injuries, Warmaster Horus leads the triumphant Imperial forces against the rebel world of Istvaan III. Though the rebels are swiftly crushed, Horus`s treachery is finally revealed as the planet is razed by virus bombs, and Space Marines turn on their battle-brothers in the most bitter struggle imaginable. Ben Counter brings the opening trilogy of this epic new series to explosive life as the Horus Heresy begins!