Xenos (Eisenhorn trilogy Book 1) warhammer 40K

New to warhammer 40K universe? go there for a recommended reading order

The Inquisition moves amongst mankind like an avenging shadow, striking down the enemies of humanity with complete ruthlessness. Inquisitor Eisenhorn faces a vast interstellar cabal and the dark power of daemons, all racing to recover an arcane text of supreme and abominable power – an ancient tome known as the Necroteuch. Book I in the Eisenhorn trilogy sets a new standard in action and adventure.

omnibus here

One of the 3  inquisitor centric serie with :

ravenor

and

vault of terra