The Bunker Diary by Kevin Brooks

A kidnapped teenager wakes in a windowless underground bunker controlled by an unseen captor who monitors them through cameras and manipulates food, light, and hope. As other prisoners arrive, fragile alliances form and fracture while a diary records hunger, fear, and moral erosion. Deprivation, cruel tests, and failed escape attempts push them to the brink, exposing both desperation and resilience. The stark, claustrophobic account builds to a bleak, haunting conclusion about survival and the fragility of humanity.

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