Castle War! (Castle Perilous‪)‬

The residents of a magical castle are under attack from the castle's own evil twin in this fantasy novel from the author of Castle Perilous.

Castle Perilous is still tottering from last year's battle with the Hosts of Hell, and regaining stability proves a hard balancing act. Before Jeremy can design a program to calm the tremors of the universe, an alternative wicked reality appears that threatens to topple everything! Castle P. must face its evil twin, replete with its own dastardly doppleganger army—with the shadow self ensues as Good and Evil battle it out in the 144,000th dimension!