In the Warhammer 40k setting, the Imperium of Man is beset on all sides by threats, both internal and external. Among the most insidious are the aliens, a vast array of species that range from the orks' brutal hordes to the Tyranids' devouring swarms. The Space Marines, genetically engineered superhuman warriors, stand as the Imperium's bulwark against these threats. Within the Space Marines, the Deathwatch is a unique chapter, composed of Space Marines from various chapters who have dedicated themselves to the fight against alien threats.
: Addresses internal threats like Apostate Cardinals and "Heretek" Magos, alongside specialized Chaos entities like Spire Slayers.