The Night Lords were once among the Imperium's most potent forces, Space Marines who wielded terror as a tactical instrument. After their monstrous betrayal, they are hunted as heretics, adrift from the Emperor's light, clad in icons of death, and fighting what they call the Long War. The series follows the Tenth Company under First Claw — a warband led by the prophetic Talos, a warrior who still hears the echoes of his primarch Konrad Curze's madness and struggles to hold his broken brothers together.

Talos is the series' emotional center — a Night Lord prophet who can see echoes of pain and death, drawn from his primarch's psychic curse. He is neither hero nor simple villain: he leads with exhausted competence, maintains codes of conduct his brothers find archaic, and grieves a Legion that was never given a chance to be anything other than what it became. Aaron Dembski-Bowden is praised across all three books for making a Chaos Space Marine warband genuinely sympathetic without excusing their atrocities.

Three novels take the Night Lords from a desperate mission assigned by Warmaster Abaddon through a fractious alliance with the piratical Red Corsairs, and finally to a flight from Craftworld Ulthwé's relentless eldar pursuit — culminating on the carrion world of Tsagualsa where their primarch died and their Legion was shattered. The series is as much about the cost of damnation and the fragments of humanity that survive it as it is about the spectacular violence of the 41st millennium.