The Bastion Wars series in Warhammer 40,000 runs to 3 books. Below is the full reading order in series sequence, so you know exactly where to start Bastion Wars and what to read next.
Original summaries and chronology labels generated from the same catalog powering the atlas.
Henry Zou
When daemon-worshipping renegades invade the Medina sub-sector, Inquisitor Obodiah Roth races to find and secure a cache of ancient artefacts before the enemy can unleash their power. Backed by the Imperial Guard, he must move faster than the tide of war engulfing the region. The first Bastion Wars novel blends Inquisitorial intrigue with sweeping military campaign.
667.M41 - 999.M41
era date, medium confidence
Henry Zou
The Guardsmen of the 31st Riverine Amphibious deploy to a jungle world expecting a routine action, only to be swallowed by a brutal rebellion and a war turning against them. Set within the wider Medina conflict, the novel grinds its soldiers through guerrilla horror and the slow rot of insurgency. It is a grim, mud-and-blood Imperial Guard story that runs alongside the events of the first Bastion Wars book.
667.M41 - 999.M41
era date, medium confidence
Henry Zou
Reeling from the betrayal that cost them their leader, the renegade Blood Gorgons answer a desperate call from one of their recruiting worlds, only to find it overrun by a plague that raises the dead. The warband must wade through hordes of the undead while their own fractured command threatens to tear them apart. The final Bastion Wars novel shifts focus fully onto its Chaos Space Marines.
667.M41 - 999.M41
era date, medium confidence