Furnace: Solitary by Alexander Gordon Smith
Furnace Prison - Where death is the least of your worries. Escape is just the beginning...We thought we'd made it, we thought we were free. But we should have known there was no way out of Furnace. All we did was slip deeper into the guts of the prison: into solitary confinement, where the real nightmares live - the warden, the Wheezers, and something much, much worse. The clock's ticking. Because if we don't escape soon they will turn us into freaks - like them. Forever. In the darkness of the hole your worst nightmares come to life.