American Peter Kleist arrives in Austria to take a break from college studies and to trace his family’s history. At the airport he is greeted by his uncle Karl Hummel, who invites him to stay at his house. Peter learns from Karl that his great-grandfather, Baron Otto von Kleist, nicknamed "Baron Blood," was a notorious sadist who tortured and murdered over 100 villagers. Legend says he burned a witch named Elizabeth Hölle, who cursed him with a spell that would allow him to rise from the dead so she could take her revenge on him eternally. The Baron's old castle, once his residence, is being remodeled into a hotel for tourists, and Peter persuades Karl to take him there to see it up close.
At the castle they meet Dortmundt, the entrepreneur driving the hotel project, and Eva Arnold, Karl’s former college classmate who has been hired to safeguard the castle’s historical integrity. After a tour, Karl invites Eva to dinner at his home. During the meal, Peter brings up the subject of Baron Von Kleist, and Karl’s young daughter Gretchen Hummel claims she has seen the Baron in the surrounding woods, though her concerns are dismissed by the adults. Peter discovers an ancient document from his grandfather’s house in America—a chilling incantation that, if read in the castle’s bell tower at midnight, would supposedly revive the Baron.
Ignoring Karl’s warnings, Peter and Eva go to the castle and read the incantation. Although they intend to perform the ritual at midnight, the bell tolls two o’clock, the same hour the Baron was murdered. A gust of wind blows the parchment into a fireplace. Peter goes outside to investigate, but there is no one there.
In the castle’s woods, the Baron rises from his grave and heads to a doctor’s office. The physician dresses his wounds, but when the doctor insists on calling an ambulance, the Baron grabs a scalpel and stabs him to death. The next morning Peter and Eva confess what they have done, but Karl urges them to forget the incident as a figment of their imagination. The Baron, however, quietly re-enters his castle and kills Dortmundt, hanging him from the ceiling. When Fritz, the castle’s caretaker, discovers the body, the Baron kills him as well. With Dortmundt dead, the castle’s restoration plans collapse and the property goes up for auction.
Alfred Becker, a wheelchair-bound millionaire, purchases the castle at the auction and offers Eva a job assisting him in restoring it to its original condition. She accepts, hoping to safeguard the place from further harm. Later, Eva is attacked in a dim corridor by the Baron, but Peter intervenes and saves her. Eva decides to quit her job and seeks a fresh start elsewhere.
That evening Eva returns home to find the Baron waiting for her in her apartment. She escapes through a window and takes refuge at Karl’s house. Convinced that the Baron is still alive, Karl agrees to help Eva and Peter find a way to destroy him. They visit Christina Hoffmann, a local medium, who conjures Elizabeth Hölle’s spirit from the netherworld for information about the Baron. Christina provides them with a magical amulet and warns that only those who raised the Baron from the dead can destroy him; as a result, he will hunt Peter and Eva with a fanatical, deadly resolve. After they leave, Christina is killed by the Baron.
On her way home from school, Gretchen is terrorized by the Baron in the woods. She eventually encounters Becker, and she identifies his eyes as those of the Baron. The trio—Karl, Peter, and Eva—confront Becker. He reveals the castle’s restored interior, complete with dummies impaled on stakes, and then springs from his wheelchair to subdue them in his torture chamber.
Eva wakes to find herself on the ground, and beside a spike-lined coffin lies Fritz’s corpse. Becker ties Karl to a rack and tortures Peter with red-hot pokers. As Eva struggles to stand, she accidentally drops the amulet onto Fritz’s body. A few drops of Eva’s blood fall onto Fritz as well, and the amulet activates a long-hidden secret: the Baron's victims rise from their coffins, empowered by the amulet and the blood of those who raised him. The undead surge forward to attack the Baron, ripping him apart. Eva unties Peter and Karl, and the three flee the castle as the Baron’s death cry and Elizabeth Hölle’s taunting laughter echo into the night.
