On an outpost Imperial world on the fringes of Tau space, Ciaphas Cain and his regiment of Valhallan Guard, find themselves in the middle of a war. As the Imperial Guard struggle to contain worldwide civil insurrection, can the wily Commissar Cain identify the real villain before the planet is lost to the Imperium forever?

Read it because

It's your introduction to the unique hero that is Commissar Cain, and his trusty Valhallans, including such memorable characters as the obnoxious Corporal Sulla and, of course, Cain's malodorous aide Jurgen.