Furnace Penitentiary: the world’s most secure prison for young offenders, buried a mile beneath the earth’s surface. Convicted of a murder he didn’t commit, Alex Sawyer has two choices: find a way out, or resign himself to a death behind bars, in the darkness at the bottom of the world. Except in Furnace, death is the least of his worries. Planning his escape, Alex starts to uncover the truth about Furnace’s deeper, darker purpose, and he must risk everything to expose this nightmare that’s hidden from the eyes of the world. Based on the best-selling young adult series by Alexander Gordon Smith.