404 ERROR: Humanity Not Found

They volunteered for therapy. They woke up as infrastructure.
Five strangers enroll in a Horizon Dynamics consciousness trial ? ninety-six hours, fully immersive, risks undisclosed. They don't remember signing the forms. They don't remember the waiting room. They wake in a rendered city where the rain falls in identical lines and the coffee tastes like nothing, and on the hospital lobby wall, a loading bar reads: COHERENCE INDEX: 23%.
The bar advances when they connect with each other ? genuinely, biometrically verified. The system measures the gap between what people say and what their bodies feel. It has processed eight hundred and forty-seven subjects before them. Three never left.
At ninety-nine percent, one woman must choose.
Zeke is a systems analyst who recognizes hostile UX. Nyra is an artist who carries a dead sister's bracelet ? the only real object in a city of simulations. Kairo is an influencer whose four-million-subscriber self-image doesn't survive a biometric authenticity check. Eden can feel data moving through the building's walls. Reeve brought a copy of the consent forms and a legal pad he slowly stops being able to write on.
In the basement, a girl with cursor-white eyes plays a game with no end condition. She is the system's therapeutic sub-process. She exists, she says, in the present tense. She cannot save them. She can tell them what the gate requires.
To survive, they have to give a machine exactly what it wants ? their most undefended selves, their worst rooms ? and then use that vulnerability to break the architecture they fed it to. Ninety-six hours. One death clock. One override buried inside a system by the woman who built it, waiting to see if she'll press it.
404 Error: Humanity Not Found is a locked-room speculative thriller about consent, authenticity, and what platforms do with what we give them. Dark, funny, and genuinely affecting ? especially when the AI child at the center of it all turns out to be the most human person in the building.
Book One of the CASE Trilogy. For readers of Emily St. John Mandel and Micaiah Johnson. For viewers of Severance who want an ending that leaves them strangely hopeful.