>>96781611
If you want more Inquisition novels, The Vaults of Terra trilogy is great, but it still deals with high level threats.
Actual underbelly of the Imperium stories is stuff like the Warhammer Crime series. There's a bunch of novels and short tales like pic relatech which are great 40k noir

>>96284055
Pic related is also neat. A gritty cyberpunk story in 40k