Baron Boris von Frankenstein, an eccentric scientist, successfully discovers a formula capable of destroying all matter. To announce his retirement and reveal his groundbreaking discovery, he decides to host a convention at his isolated island castle. He plans to gather all the famous monsters, including Dracula, the Wolfman, the Mummy, and the Invisible Man. Amidst the expected guests, Frankenstein also invites his clumsy, unassuming nephew, Felix Flanken, with the intention of naming him as his successor, much to the chagrin of the other monsters.

The convention becomes a hotbed of rivalry, deception, and intrigue as the monsters vie for control of the Baron’s secret formula. Meanwhile, Felix, unaware of the dangers surrounding him, attempts to navigate the treacherous environment with the help of Francesca, the Baron's alluring and mysterious assistant. As tensions rise, the monsters' ambitions lead to comically chaotic situations. Felix's innocence and clumsiness result in unexpected consequences, creating a whimsical and unpredictable atmosphere amidst the looming threat posed by the powerful formula.