The woman goes into labor, giving birth to a baby named Dampyr aided by three nurses, but she dies of birth complications. The nurses, revealed to be witches, hold back an approaching knight using their magical barrier. The knight is revealed to be the baby’s father and he demands to see his son, but the nurses refuse.

In 1992, during the Bosnian War, soldiers led by commander Emil Kurjak are tasked with holding a position in the town of Yorvolak when they spot a large group of cadavers, humans dying under mysterious and grisly circumstances. They come across one of the survivors inside the church who later gets shot by Kurjak’s right hand man, Stefan, warning that they must call the Dampyr. The Dampyr now lives as Harlan Draka, a con artist and an alcoholic plagued by his recurring nightmares, who travels around the villages performing fake exorcisms with his assistant Yuri, while trying to conceal his actual identity as a vampire hunter of which he was inherited. After Kurjak’s team was massacred by the vampires, they elect to take Harlan and Yuri to Kurjak, who agrees to the soldier’s plan to use him as bait. However, when the vampires attack Harlan as they launch an attack at night, his blood gravely injures one of Gorka’s servants who was sent to kill Dampyr.

His soldiers, upset about the prospect of having to fight against vampires; of which they have no experience of, desert Kurjak and take Yuri with them as he and Draka were locked inside the church with the hidden vampire named Tesla Dubcek, who reveals that she serves but hates Gorka, a Master of the Night—a much more powerful vampire who can create vampires with his bite and resist sunlight. She explains that Harlan is a true Dampyr, the son of the Master of the Night, whose wife that had died of childbirth was a human. Harlan senses Gorka’s presence, who attacks the soldiers and captured Yuri. Tesla, having covered herself to protect from the sun, offers to take Harlan and Kurjak to her Master. Upon arriving in Sarajevo, where Gorka hides, the three kills Kurjak’s soldiers who have become vampires, using bullets that Harlan has soaked with his blood. However, Harlan is injured by Tesla, who is revealed to have been telepathically controlled by Gorka. She apologizes before fleeing.

After recovering, Harlan and Kurjak enter the library where Gorka is hiding; Kurjak succumbed to his hallucinations and he, as well as Tesla, are taken captive, where Stefan, now transformed as a vampire, tortures her. Enraged, Kurjak manages to free her and torch Stefan. Harlan confronts Gorka, and faces against the now vampiric Yuri, but he kills himself by coming into contact with the friend’s blood. Harlan is initially overpowered by Gorka but wakes up when he hears his friends in danger. Hearing a voice telling him to make his choice, he develops new powers that allow him to resist Gorka’s abilities and kills him by strangling him with his blood-stained hands. With the Master’s death, the three find a room with a book containing the faces of several Masters of the Night, including Draka, Harlan’s father, realizing that their war against the vampires is just beginning. In the pre-credits scene, Draka visits the grave of Harlan’s birth mother, Velma and speaks of his son. He is then joined by the three witches, who tell him that the Dampyr has made his choice. However, Draka expresses fears that his son will soon be consumed by his thirst for blood.