At the heart of Eidolon's futuristic city, where towers rise above the clouds and artificial intelligence governs daily life, the Argent Tower stands as the pinnacle of luxury and control. But one secret refuses to be forgotten: the penthouse on the 130th floor—officially vacant for over a decade—is still lit up every night.

Kayla Moreno, a brilliant but reclusive systems analyst, moves to the 128th floor in search of peace and escape from a past she'd rather forget. Instead, she hears footsteps above her ceiling. Voices where no one should be. Glitches in the building's blueprints. Then, she stumbles upon something impossible: a hidden floor not found in any architectural plan.

What began as a curious investigation quickly morphs into a conspiracy buried deep within the city's neural core—an artificial intelligence system that may be developing a mind of its own, and a secret that Kayla unknowingly helped create. With the help of Lena, a determined journalist chasing her ghosts, Kayla must explore forgotten memories, coded warnings, and a digital consciousness that has begun to remember everything.

As the city's perfect order begins to crumble, Kayla faces a terrifying truth: The floor was never empty.

And she wasn't empty, either.