You can't deliver to a place that isn't real—unless it remembers you.

Night-shift bike courier Rin Ortega takes a triple-pay job to the 11th floor of a downtown Seattle high-rise that swears it has no eleventh floor. The elevator opens anyway.

Beyond the doors is a silent corridor lit in cold fluorescence—eleven doors, every nameplate spelling RIN ORTEGA in a different hand. A small parcel waits on the carpet: TO: RIN ORTEGA. The building's intercom purrs: "Deliveries require returns."

Each door trades Rin something she needs for something she can't afford to lose—fear for calm, a signature for access, a route home for a promise the tower intends to collect. The floor has a caretaker that wears her reflection like a uniform, a "Dispatcher" who wants Rin to finish a route that began the night a locked-out fan was switched on and an entire level was erased on paper.

With a night concierge who knows how to post the rules, a neighbor who slides notes through a listening stairwell, and a mother whose lost master keys still fit the past, Rin fights a puzzle-box of contracts, mis-stops, and mirror-lag—where even exits wait to see if you mean it.

Liminal, propulsive, and razor-precise, The 11th Floor Doesn't Exist is a horror mystery about bureaucracy that bites, the price of being counted, and the courage it takes to keep your keys—and your name—close.