As Halloween is about to arrive, Count Dracula decides to host a party in his castle and perform a concert along with "The Horrors", a rockabilly band he formed back in the 1950s alongside Harry the Wolfman and Frank, the Frankenstein's Creature. He asks his Brides, Mikaela, Daphne, and Les, to go to Transylvania and spread the news.
The Brides go to the city and hypnotize different radio hosts to inform the public about the concert. After finishing their labor, the Brides are invited by Oliver and the Oligarch Anarchs, a local rock band, to go to their gig. The Brides agree, unaware that there is a mysterious van following them.
As Daphne and Les try to enjoy the gig, Mikaela searches for solitude and meets Andrea, a goth girl with a crush on her. As Mikaela and Andrea walk around the city, the mysterious van arrives and captures Mikaela. Andrea escapes and informs Les and Daphne. As their true identities are revealed to Oliver and the Oligarch Anarchs, Les wants to kill them (and Andrea), but Daphne persuades her to join forces with them to find Mikaela faster.
Mikaela wakes up in a laboratory belonging to Dr. Van Helsing and discovers that he has been following them all night. Van Helsing reveals that he plans to capture all the Creatures of the Night so he can make experiments with them and terrorize the people who once called him a madman.
With Andrea's help, Daphne and Les arrive at his laboratory and try to save Mikaela, but are defeated by Van Helsing's latest invention: a gas that puts vampires to sleep. However, Andrea and the boys break into his lab and rescue the Brides.
Andrea and the boys take the Brides to Andrea's house. The Brides awake hypnotized under Van Helsing's gas and attack them. As they are about to kill them, Andrea accidentally turns on the radio and, as the music begins to play, The Brides are released from the hypnosis. They apologize and decide to stop Van Helsing. Since they are still weak, they ask the boys to take them to Van Helsing's lab.
Mikaela apologizes to Andrea for having tried to kill her twice (once when Andrea first found out about her true identity, then when she was under hypnosis) and expresses the disgust she feels of being a vampire as the eternal life has made her a tired person with nothing to live for anymore. Andrea forgives her and expresses her wish to become a vampire and join her in the darkness, which Mikaela refuses to do.
The Brides arrive at Van Helsing's lab but discover that the place has been abandoned. As they try to figure out how could Van Helsing capture all Creatures of the Night, Mikaela comes to realize that Van Helsing is planning to use the same gas that he used on them and that the only way he can do this is from an abandoned mansion on a high hill.
The Brides go to the abandoned mansion and find Van Helsing, who has already released the gas and shows how everyone in Dracula's castle is already under hypnosis and that only he can release them from it. The Brides refuse to surrender and fight Van Helsing and his men. They kill Van Helsing, but he manages to shoot a silver bullet to Mikaela's chest. Les takes out the bullet and Daphne searches for Andrea so Mikaela can drink some blood and recover herself.
As the sunrise is about to arrive, the Brides discuss what to do to release the Creatures of the Night from Van Helsing's hypnosis. The boys inform them that what released them was music. The Brides, Andrea, and the boys head to Dracula's castle and perform a little concert that releases the Creatures. The Brides say goodbye to the boys and Andrea and invite them to their party the next night.
Halloween night finally arrives and Dracula and his band perform a hell of a concert alongside the boys. As everyone has fun and dances, Mikaela takes Andrea to her room. They make love and Mikaela grants Andrea her wish, turning her into a vampire.