What is a soul, exactly? When 'Frankie,' the Frankenstein monster, discovers he lacks a soul, he becomes determined to acquire one so he can marry his girlfriend, Izzy. Frankie seeks help and returns to Castle Frankenstein, where he surprises Dr. Victor von Frankenstein and Igor. Although they are reluctant at first, they eventually offer their assistance. During their studies at Castle Frankenstein, they encounter Dr. Nabil Ur Thoth, who offers his help. At Nabil's request, they journey to Egypt, where they face numerous dangers and have life-altering adventures. Back in Transylvania, after a series of mishaps on a midnight walk in the woods, Count Dracula, The Wolfman, and Imhotep the Mummy all end up trapped in Frankie's body, leading to hilarious but potentially disastrous results. Can 'the boys' learn to get along despite being natural enemies? Can they grasp the science behind this mishap? Most importantly, can they save the world from a madman and help Frankie find a soul?