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!