Hellfighters (The Devil's Engine, #2)

Thrown into a relentless war against the forces of darkness, fifteen-year-old Marlow Green and his squad of secret soldiers must fight for control of the Devil’s Engines―ancient, infernal machines that can make any wish come true, as long as you are willing to put your life on the line. But after a monstrous betrayal, Marlow, Pan and the other Hellraisers find themselves on the run from an enemy with horrific powers and limitless resources―an enemy that wants them dead at all costs. Failure doesn’t just mean a fate worse than death for Marlow, it means the total annihilation of the world. And when all looks lost and the stakes couldn’t be higher, just how far is he willing to go?