The Devil's Engine: Hellfighters: (Book 2) (Devil's Engine") <2>

"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"--