During the late 19th century Dr. Frankenstein works with Count Dracula to bring the dead back to life. In doing so he creates Frankenstein's Monster. Dracula disposes of Frankenstein and the monster goes into hiding.

One year later Van Helsing is sent to Eastern Europe by a secret religious organization with ties to the Vatican in order to vanquish Dracula and save the family of the beautiful Anna from eternal purgatory. Long ago, an ancestor of Anna swore that he and his descendants would not enter Paradise until Dracula was destroyed.

Dracula tries to use Igor (Frankenstein's assistant) and Frankenstein's equipment to animate his offspring, which are born dead. However, without Dr. Frankenstein's expertise these attempts fail.

Van Helsing discovers that Dracula cannot be killed by the 'conventional' methods of disposing of a vampire, and also that Dracula knows of him. With Van Helsing's memory fragmented, he finds this curious.

Meanwhile, Dracula uses Frankenstein's monster as a catalyst to start a chain reaction that successfully animates Dracula's dead children.

Count Dracula is able to control werewolves after their first full moon, having them do his bidding; however, this is an ironic ability of Dracula's, because only a bite from a werewolf can kill him. One of those who suffers from this control is Velkan Valerious, son of the Gypsy King Boris Valerious; despite the fact that his family had been hunting Dracula since 1462, Velkan falls under the curse when he's bitten by one of Dracula's previous wolves while protecting his sister Anna from it. He was later killed by the monster hunter Van Helsing, but not before biting him, giving him the power to finally kill Dracula. Van Helsing finally kills Dracula in a showdown during the next full moon.

Anna injects Van Helsing with the antidote to the werewolf curse, which Dracula keeps in his castle to protect himself, and Van Helsing reverts to a human after unwittingly killing Anna. Frankenstein's monster sails off into the sunset. Van Helsing burns Anna's body in a funeral pyre, and sees a vision of her entering Paradise with her ancestors.

Notes

The film contains numerous homages to the Universal Studios horror films of the 1930s and 1940s, particularly those featuring Dracula, Frankenstein's Monster, and the Wolf Man. A poem/legend specifically written for The Wolf Man is quoted verbatim in this film.

Although this film is an homage to the Universal monster series, it breaks a cardinal rule by referring to Frankenstein's Monster directly by the name "Frankenstein", although in the context of this film, The Monster clearly considers himself to be Frankenstein's son. This difference is further borne out in an additional scene in the film's tie-in novel, in which the Monster specifically tells Van Helsing to call him Frankenstein.