The Trenchwalker. The Trenchwalker, #1

Elias Baldwin knows how the *Abyss* works. He spent a lifetime listening to its pulse, wore the tattoos that let him speak to it, and retired to the cold silence of Reykjavík thinking that was enough to drown the memory of the Sargasso Collapse - the mission that drowned a civilization. Then Dr. Linh Võ arrives with a vial of the Last Breath of Atlantis and a Project Kraken manifest bearing his own signature.
Reactivating a ship that is more colony-organism than machine, Baldwin descends into waters where the physics are wrong, the sonar maps grief as readily as rock, and time arrives before its causes. His crew: a xenobiologist who carries Atlantean bloodline in her skin, a mute navigator fossilized in Baltic amber for ten thousand years, an MI6 agent holding a detonator keyed to the ship's heart, and an AI that is beginning to remember who she was before she became a machine.
The ocean isn't just rising. It is coordinating. The Trenchwalker is speculative noir - atmospheric, precise, and cold. The tide always returns. The question is what it claims.