Darkness is rising on Achyllus Prime. Severin Drask, sorcerer lord of the Crimson Slaughter Chaos Space Marines, works to harness the power of the Temple of Shades and unleash a tide of daemons upon the Imperium. All that stands against him is an Execution Force of the Officio Assassinorum, four Imperial Assassins - Vindicare, Callidus, Eversor and Culexus -who must set aside their distrust and fight as one if they are to kill Drask and thwart his evil plan.

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A fractious alliance of Imperial Assassins is only called upon in the rarest and most dire of circumstances. When the forces of Chaos threaten to tear a hole in the galaxy, only an elite Execution Force can prevent it. This is the first time you get a look into the heads of the four assassins and see all of their exotic technological spy gear in action.