From the back cover:
The Enemies of Man are Legion. The Alien, the Beast and the Daemon are but a few of the horrors lurking in the shadows. The Inquisition's mandate is to bring the Emperor's Light into the darkness and utterly extinguish those that oppose the might of the Imperium.
A variety of menaces, from the Fenksworld Pit to the Xothian Blood Locusts, plus an overview fo the Calix Sector's infamous Deathworlds.
Assessments and counsel from notable members of the Inquisition on exterminating each foe.
Destroy these foul creatures in the Emperor's Name.