Scourge the Heretic - Mitchell Sandy

The human Imperium is a dark, dangerous place. While Space Marines and the Imperial Guard battle aliens among the stars, it is the job of the Inquisition to hunt down the heretics who corrupt society from within. When an Ordo Hereticus warband is sent to investigate an inter-planetary people-trafficking operation, they soon find something much more sinister than people being smuggled and suddenly they are up against some very dangerous enemies indeed.