Assassinorum: Execution Force

Darkness is rising on Achyllus Prime. Severin Drask, sorcerer lord of the Crimson Slaugher 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.

Read it because
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.