Rogal Dorn’s punitive fleet arrives in the Isstvan System, ready to bring Warmaster Horus before the Emperor to face judgment. Yet the loyalties of the Legions assembled to crush the traitor army are not always what they seem. Conspiracies and hidden agendas disrupt the mission, creating an environment where betrayal and duplicity threaten every maneuver, and where each decision carries dramatic consequences on the battlefield.

Before the day ends, a Primarch falls on the black sands of the Urgall Depression, marking a brutal and irreversible turning point in the galactic civil war. The novel captures the brutality, strategy, and tragedy of this critical period, allowing the reader to feel the scale of the disaster and the tension between loyalty and treachery. This book is essential for anyone seeking to understand the events leading to Horus’s march on Terra and the lasting impact on the Imperium.