Dan Abnett
Master Imus's Transgression
Eisenhorn (series)
Master Imus, a mild-mannered clerk, has a confession to make – he has unwittingly conspired in a crime…
Warhammer 40k
short

Also in:
There Is Only War
The Agents of the Imperium Audio Collection
Lord of the Dark Millennium
Thorn And Talon
The Magos