In the original novel, Barlow came to the town of Jerusalem's Lot in a box shipped overseas by his assistant, Richard Straker. The two then took residence in the Marsten House, an abandoned house that was considered haunted by the townsfolk. After he posed as an antique dealer, Straker kidnapped a local boy, Ralphie Glick, and made a human sacrifice of the child in an appeasement ritual. Ralphie's brother, Danny, became a vampire and began to infect others, including his mother, Marjorie. Late at night, Barlow came upon unhappy and frustrated Dud Rogers, a hunchbacked dump custodian, laughed at by the young woman that he craved, Ruthie Crockett, daughter of businessman and real estate broker Larry Crockett, who signed the real estate contracts with Straker to purchase the Marsten House and the site that became the antique store front that was used by Straker. Barlow also came upon Corey Bryant, a young telephone worker who was tortured and ordered to leave town by Reggie Sawyer, the man Bryant was cuckolding. After he knew everything that happened, Barlow lured Bryant under his hypnotic spell, promised them the spoils, i.e. Ruthie Crockett and Bonnie Sawyer, and drained both men of their blood on the spot.
Danny later paid a night-time visit to one of his schoolmates, Mark Petrie. However, Mark, an intelligent and resourceful child, identified Glick as a vampire and drove him off with a plastic cross. Mark then sneaked into the Marsten House the next day with Susan Norton and intended to kill Barlow. However, they were both captured by Straker: Susan was bitten by Barlow and became a vampire, but Mark managed to escape and mortally wounded Straker in the process. Straker was later found hanging upside down and drained of his blood by Barlow, who could not resist punishing him. Petrie informed Susan's boyfriend, writer Ben Mears, of Susan's fate, and became part of the effort to kill the town's vampires, together with Ben, Catholic Priest Father Donald Callahan, Dr. Jimmy Cody and the Lot's high school English teacher, Matt Burke. Susan visited Mark at night, entreated him to let her in as "there are lots more of us now," and promised to "kiss him all over." Mark then drove her away, as he had Danny Glick use the same plastic cross.
When Father Callahan and Mark headed over to Mark's parents to explain the danger that the family was in, the power was suddenly cut and Barlow appeared. He killed Mark's parents by smashing their heads together, but did not infect them. Barlow then took Mark hostage briefly. Callahan pulled out his cross in an attempt to drive Barlow off, and for a time it worked, until Barlow challenged him to throw away the cross. Callahan, who did not have faith enough to do so, was soon overwhelmed by Barlow, who took the useless cross, snapped it in two, and forced Callahan to drink his blood.
Mark escaped, as part of Barlow's deal with Callahan, and warned the others. The last time that Barlow was seen was at the end of the novel, where he was killed by Ben and Mark in the basement of Eva Miller's boarding house.
In Salem's Lot (1979), Barlow was significantly different from his novel counterpart; while Kurt Barlow in the novel resembled an ordinary human being, in the 1979 mini-series, he was depicted with a Nosferatu-like appearance. Interestingly enough, in The Dark Tower, it was mentioned in the beginning that "Type One" Vampires (such as Barlow) were horribly disfigured, mutant-like creatures whose teeth grew out so wildly that they couldn't close their mouths. Also, that Barlow never spoke and only growled and snarled. Considering his position as a Master Vampire, it was possible that Barlow was an incredibly potent telepath who had no need for speech.
That version of Barlow had a variety of Supernatural powers, such as Telekinesis: Barlow opened a locked cell door with a wave of his hand, moved his own coffin along with the crate (which was unnaturally freezing cold to the touch) that it was inside, and caused the Petries' entire house to shake before he entered. Unlike other vampires, Barlow was able to enter a person's house without an invitation. Like Count Dracula, Barlow appeared to have the ability to be active during daytime; he turned Susan into a vampire after Straker brought her to him during his daily sleep, though that occurred in the Marsten House's basement and was off-screen. As such, it was never definitively revealed if that incarnation of Barlow could have withstood sunlight. 1979's Kurt Barlow was portrayed by Reggie Nalder.
In the 2004 miniseries, Barlow was portrayed by Rutger Hauer. Barlow was a sophisticated, well-dressed older gentleman and, at first glance, his only difference from the rest of the community was his mildly anachronistic appearance (his dress and behavior seemed to have came from an earlier time). As opposed to the Nosferatu-type creature that Barlow was portrayed as in the 1979 mini-series, that version of Barlow was more akin to the more romantic versions of Count Dracula, although he still had glowing eyes. That portrayal of Barlow was more in keeping with King's original novel.
Barlow was described as having a white face with long, sharp, needle-like fangs and red, glowing lurid eyes. Barlow also had long, sensitive fingers, like those of a pianist.