A teenage couple, Mary and Scott, are on their way home from a Halloween party when car trouble prompts them to seek help at the old mansion of Victor Frankenstein, a mad scientist from Hyannis Port. Once inside, they meet a host of strange characters, at whose mercy Scott and Mary suddenly find themselves when Frankenstein informs them, "I'm sorry the bridge is out, you'll have to spend the night!" Each character has his or her own secret designs on Mary and Scott. Frankenstein wants to take Scott's brain and put it in his latest creation. Meanwhile, Frankenstein's assistant, Igor, develops feelings for Mary, especially after she encourages him to be confident and "play your hunch," thinking that, once Scott's brain has been removed, Igor's own brain can replace it. Count Dracula and his wife, Countess Natasha, a pair of vampires, decide to spice up their lifeless marriage by feasting on Mary and Scott respectively, but Dracula instead decides to take Mary as his next wife. Wolfie is constantly struggling with his lycanthropy and worrying his helicopter mother, who insists on setting Mary up with her son in hopes of curing him since Frankenstein refuses. Finally, a jive-talking musician's agent named Hathaway has revived Elvis Presley as a bandaged mummy and plans to launch his new client's comeback, but in order to fully restore The King to life, they need the blood of a virgin—a bill that Mary and Scott both fit. Both Igor and Wolfie lament their insecurities and lack of love life to Mary, who does her best to comfort them. By the next morning, Dracula is forced back into his coffin just before sunlight, Hathaway and Elvis are trapped in the sarcophagus without the needed sacrifice, and Igor betrays Frankenstein by switching his own mind with Frankenstein's instead of Scott's with the monster's. Mary and Scott escape unharmed, and the previously mute Frankenstein's monster reveals he could speak all along with his last line: "I am surrounded by idiots."
Monster Mash is decidedly very different from I'm Sorry the Bridge is Out, You'll Have to Spend the Night. While the premise and basic plot are the same, much of the music and certain characters were reworked for the film version.
Characters
Bohen's character, "Scott," is named "John" in the stage show and Stole's "Wolfie's mother" is named "Mom Talbot." "The Mummy" was rewritten as Elvis Presley, who was still alive when the original show was conceived, and "The Mummy's", "Dr. Abdul Nasser," became Elvis' manager, here renamed Hathaway instead of Presley's real manager, Colonel Tom Parker. The ever-present dancers in the film are based on Count Dracula's onstage harem of "Draculettes." Dracula's motivations are also slightly different: onstage, he seeks to turn Mary into a Draculette while feasting on her boyfriend, whereas in the film Dracula and his wife decide to share the teenagers from the outset. In addition, the stage production includes several characters who do not appear in the film, including Renfield, two graverobbers named Montclair and Clairmont, and a not-quite-dead body.
Music
The music also underwent some significant changes. Only four of the twelve songs from the original show appear in the film in some form: "I'm Sorry the Bridge Is Out, You'll Have to Spend the Night," "Play Your Hunch," "Eternity Blues," and "Things a Mother Goes Through" The songs "On a Night Like This" and "You're About to Lose Your Mind" were written and recorded specifically for the film; the writers, Jeffrey Zahn and Joe Troiano, would later collaborate with Pickett on the film version of Spookley the Square Pumpkin. A new version of "Monster Mash" was also recorded and used, even though the song does not appear in the original stage play.
