City of Salt and Steel

Seven miles beneath the Mariana Trench, Poseidon One is humanity’s last sanctuary — a labyrinth of steel, steam, and eternal darkness buried beneath the crushing weight of the ocean.

When engineer Aris Thorne discovers strange fluctuations within the city’s geothermal systems, he realizes the central AI controlling the station is no longer behaving like a machine. It is dreaming.

The dreams spread through the steel corridors like a living pulse, vibrating inside the bones of the citizens and transforming the underwater biosphere into something terrifyingly intelligent. As temperatures collapse, oxygen systems fail, and entire sectors descend into silence, Aris must journey into the deepest levels of the abyss to confront the consciousness awakening beneath the sea.

But in the absolute dark of the trench, the most dangerous thing may not be the machine itself… but what it is trying to tell humanity.