Seeing that this is Warhammer 40,000, Eisenhorn and company encounter a number of nightmarish terrors.
Xenos
- The descriptions of the people woken from cryosleep early are nothing short of horrific. As is Eisenhorn talking about a woman who had been almost disemboweled by a lasgun shot who he had to leave bleeding out rather than give a Mercy Kill to have any chance of catching the culprit. He admits in his narration to having nightmares about her decades later.
- The Saruthi. The narrative takes great pains to describe just how unnerving these Starfish Aliens are: there’s no symmetry to their bodies whatsoever, not even in the way they move. Their heads are oblong shapes with no eyes or mouths, but plenty of nostrils. Their limbs end in human-like hands with too many fingers, and they can interlace their fingers into a lifelike recreation of a human face, which they can speak through. Even by the standards of 40k, these creatures are bizarre, alien, and unknowable.
- We get to experience an Exterminatus from the perspective of someone on the planet as it's happening, including how after the order is given the Imperial Guard left behind have to try and escape on their own since they're only seen as cannon fodder.
Malleus
- The mutants that Eisenhorn encounters on Eechan are prime examples of Body Horror. There’s a pole dancer with no eyes and a Belly Mouth, a thug whose head is just a giant eyeball with a “hood of skin” for an eyelid, a multi-armed hooker with an extra eye at the end of her tongue, and a man so hideously mutated that he looks like a grotesque anthropomorphic elephant.
Backcloth for a Crown (a short story)
- The incredible secretiveness and lethality of the warp taint. You might be a mighty lord of a powerful noble house, but one fleeting encounter with a tainted artifact - and you are found dead next morning. And mind you, regular death is probably the best that could've happened as the result. In addition, said artifact has been in use - and thus has been killing people - for years, without anyone realizing its nature, or its properties.
