Stratagem: The Horus Heresy Series (Unabridged‪)‬

After returning from Calth and the Underworld War, Sergeant Aeonid Thiel is summoned before his primarch Roboute Guilliman. The fragile peace of Imperium Secundus is threatened by traitor warbands left behind by the Shadow Crusade, and a new order of battle must be written.