The story begins with a woman going into labor and delivering a baby named Dampyr, assisted by three nurses. Tragically, the mother succumbs to complications from childbirth. These nurses are later revealed to be witches, who use their magical powers to defend against an approaching knight. This knight turns out to be the father of the newborn, demanding to see his son, yet the witches refuse.
Fast forward to 1992, amidst the chaos of the Bosnian War, a contingent of soldiers led by commander Emil Kurjak is dispatched to the town of Yorvolak. There, they are confronted with the grim aftermath of a massacre. An elderly survivor, filled with fear, insists that they must call upon the Dampyr. Unfortunately, before they can react, he is shot by the heartless soldier, Stefan, serving under Kurjak. As the soldiers attempt to regain control, they are ambushed by vampires. Amidst this turmoil, Lazar and Dejan manage to bring the Dampyr—the now revealed Harlan Draka, a disillusioned alcoholic con artist known for his fraudulent exorcisms—into the fray. Harlan, who is tormented by nightmares and reluctant to acknowledge his lineage as a vampire hunter, is forced by Kurjak to serve as bait for the vampires.
As vampires attack the town, Harlan discovers that his blood has the unique ability to harm them, forcing a retreat. Caught in the midst of this battle, Stefan resists Kurjak's orders, imprisoning him within a church alongside Harlan and a lone surviving vampire named Tesla Dubček. Harlan’s manager and assistant, Yuri, is sent away for his protection. Inside the church, Tesla, who harbors a resentment for Gorka—a Master of the Night, reveals Harlan’s true nature as the son of a vampire and warns that Gorka sees him as a direct threat.
As the confrontation escalates, Gorka's malevolent presence becomes palpable, capturing Yuri in his clutches. Harlan implores Tesla to lead him to Gorka. Together, they journey through ravaged Sarajevo to a library where Gorka is thought to hide. Encountering transformed soldiers, including Lazar and Dejan, Harlan employs bullets soaked in his blood to vanquish them. However, Gorka, manipulating Tesla's will, forces her to betray Harlan by attempting to shoot him.
After regrouping, Harlan and Kurjak confront Gorka in his lair, yet they face considerable hardships as Kurjak suffers psychological torment from visions of his deceased son, Miklos. As tensions rise, they find themselves captive alongside Tesla. In a desperate act to escape, Kurjak sets the vampiric Stefan ablaze, allowing them to break free. The final clash between Harlan and Gorka commences as Harlan fights against Yuri, who succumbs to the touch of Harlan's blood.
Despite the overwhelming power of Gorka, Harlan, urged by a dark knight’s voice, taps into newfound abilities that enable him to resist Gorka's magic. The conflict concludes as Harlan manages to conquer Gorka, ultimately strangling him with blood-stained hands, marking a pivotal moment in their struggle.
In the aftermath of Gorka’s defeat, they uncover a room filled with a book bearing the likenesses of numerous Masters of the Night, including Draka, Harlan's father, signaling that their battle against the vampire clans has only just begun. In a haunting pre-credits scene, Draka pays his respects at the grave of Harlan's mother, Velma. Meeting with the three witches, he ominously proclaims that the Dampyr has made his choice, warning that Harlan's hunger for blood may soon overwhelm him.
