Saturday the 14th

Waldemar and Yolanda, two vampires from Transylvania, are on the verge of securing a new home in Erie, Pennsylvania. Their excitement, however, is soon overshadowed when they discover the house is already inherited by a new family.

John and Mary attend the reading of a will, learning that John's deceased uncle has left them a charming yet in disrepair house. Despite rumors of a curse, they are captivated by the property, although their children are less enthusiastic.

The family moves into the house that night. While attempting to get comfortable while watching television, Billy discovers a mysterious book in the library, despite warnings inscribed within it about the dangers of opening it.

Billy, unable to resist curiosity, opens The Book of Evil, releasing chaos into their lives. That night, he is horrified by a monster in his room, while Mary becomes a victim of Waldemar's bite, creating a night of terror for the family.

As John and Mary shop for curtains, Billy finds out his mother has moved The Book of Evil. Meanwhile, Debbie faces a terrifying encounter with a gill-man creature in the bath, while Mary gets overwhelmed by a swarm of bats in the attic.

The family decides to call in exterminator Mr. Van Helsing to help deal with their bat problem. He confidently reassures them that getting rid of bats is a process and not an overnight affair, despite their mounting fears.

During a family dinner, Billy reveals he has lost The Book of Evil, alarming Van Helsing. Van Helsing warns that the world is at risk if the book isn't found, heightening the stakes for the family.

As Saturday approaches, the family prepares for a gathering. However, panic strikes when Billy goes missing, prompting guests to search for him frantically throughout the house and grounds.

Just before midnight, Waldemar and Yolanda arrive unexpectedly, bringing Billy and The Book back. The peaceful gathering soon turns into chaos as monstrous beings close in on them, increasing the tension.

In a dramatic standoff, Billy confronts Mr. Van Helsing, realizing he is one of the monsters. As tensions rise between Van Helsing and Waldemar, it becomes clear that darkness surrounds them all.

In a climactic moment, Van Helsing seizes The Book of Evil and vanishes with it into thin air. Instead of freeing the monsters, the book's destruction eradicates them, lifting the dark curse hanging over the family.

On Sunday, as dawn breaks, John, Mary, Debbie, and Billy make a decisive escape from the haunted house that has caused them so much pain and terror. Meanwhile, Waldemar and Yolanda finally claim the home they fought for.