While investigating a sudden surge in the Earth's monster population, the internally embattled Four Who Are One- along with their newest recruits, Christine 16 and Mr. Speed- are sucked into another, terrifying dimension. This horrifying, desolate world- as well as the monster crisis that's taken the Earth by storm- is clearly the work of the Unholy. Soon, our heroes' greatest fears are brought to life and inflicted upon each of them, rendering each one crippled with despair and self-loathing, while the Unholy's powers grow ever stronger. Can KISS make it out of this alive- and save the future of humanity in the process- or will their petty, human differences seal their ultimate fate?