Aldrich Isengrund, a dead man from 2027, claws his way out of a cryo-sarcophagus surrounded by skeletons. He remembers his death: a Warhammer miniature spear, sewer filth, sepsis, and a desperate cryogenics deal. Armed with a steel pipe and a growing understanding that he can see in total darkness, he explores the ruined Federation station. A manta-ray demon attacks him in the canteen; he beats it to death, and its dissolving corpse triggers his E-SIM implant. The module announces itself with a voice like grinding machinery, explaining that it improves body, mind, and soul through energy, knowledge, and kill count. The final message from a man named Adam burns into his mind: Good Luck. He knows now that he is in the 41st millennium, and there is only war.

Aldrich ventures into Ork territory and meets Bola, the gretchin who threw stikkbombs at a bloodletter. They strike a deal: tools and scrap for a big gun. Bola fleeces him, but Aldrich has no choice. He builds a workshop, crafts a slugga for the gretchin, and sets traps for the Orks. The real prize is the STC Library, a ruined temple of technology. He finds nothing but ash and broken shelves. Weeks of labor yield only a single STC for a Cargo Container. Disappointed, he turns to the Distant Sun, a Mechanicus cruiser embedded in the hulk. The deal with Bola is a lifeline, but it also reveals the precariousness of his position: he is a lone human in a xenos-infested hell, and his only ally is a conniving gretchin.

Aldrich faces a Chaos Marine in the station's generator room. He survives by detonating promethium-soaked squigs, but the Marine kicks him down the corridor. In a desperate gamble, he shoves his pipe through the Marine's neck and severs his limbs with his power field. The kill gives him a rush of power and a golden skull in his HUD. Later, after escaping the station and boarding the Distant Sun, he is ambushed by Eldar. They shoot him in the head and crush his lanyard. He wakes in a medicae bay, his consciousness preserved by E-SIM's distributed network. The Eldar were after the STC data on his lanyard. He survives, but the encounter shatters his confidence and reveals the true value of what he carries.

Aldrich meets Aruna, the machine spirit of the Distant Sun, a holographic brass cat that serves the vessel. He learns the ship's history: a demonic invasion, a skeleton crew, and a desperate captain who died of old age. He also finds Quaani, a young navigator in stasis beneath the spire. Quaani is the last survivor of House Rey'a'Nor. Aldrich takes him in, teaching him and protecting him. The two form a bond, with Quaani becoming a surrogate son. The discovery of the navigator's gene unlocks tier four upgrades for Aldrich, but he refuses to become a psyker. The machine spirit and the child become his only companions in the vast, empty ship.