"To defend themselves, a ragtag group of teens bands together at an abandoned amusement park after one day when, without warning, the entire human race turns against them"--Provided by publisher.

"Fifteen-year-old Marlow understands that their former leader must be stopped from using the two Devil's Engines in his control to open the gates of hell--something Boyd cannot do until he discovers the location of a mythical third machine. Marlow and Pan must take up this deadly duel with an all-powerful enemy that seems utterly impossible to win"--

After his failed attempt to escape from Furnace Penitentiary, Alex struggles to survive the bloodstained laboratories beneath where monsters are manufactured, with a death sentence--or worse--hanging over his head.

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, sentenced to life without parole, 'new fish' Alex Sawyer knows he has two choices: find a way out, or resign himself to a death behind bars, in the darkness at the bottom of the world.

Marlow Green is a high school boy in New York who is always in trouble for vandalism and acting out, until one day he stumbles into the middle of a battle with a demon, and learns about The Devil's engine--an ancient machine which can grant anything you wish for, in exchange for your soul.

After Marlow makes a deal with the Devil to get himself and Pan released from Hell, war breaks out and the friends have only each other, and hope, to combat demonic creatures and monsters.