An author returns to his hometown of Jerusalem's Lot in search of inspiration for his next book, only to discover that the townspeople are being attacked by a bloodthirsty vampire.
Ben Mears, a writer who spent part of his childhood in Jerusalem's Lot, Maine, also known as 'Salem's Lot, has returned after 25 years to write a book about the long-abandoned Marsten House, where he had a bad experience as a child. He soon discovers that an ancient evil has also come to town and is turning the residents into vampires. He vows to stop the plague of undead and save the town.
Ben Mears, a writer, returns to his childhood hometown of Jerusalem's Lot to work on a new book and soon starts a romance with local resident Susan Norton. Meanwhile, a mysterious European named Richard Straker opens an antique shop in town and moves into the long-abandoned Marsten House. Straker has a large coffin delivered to the house's basement and kidnaps middle school student Ralph Glick, sacrificing him to his master, a vampire named Kurt Barlow. Despite a search party, Ralph remains missing, and newcomer Ben is blamed. Barlow then attacks Ralph's brother Danny, who later dies and emerges from his coffin as a vampire, biting gravedigger Mike Ryerson.
School teacher Matt Burke encounters a sickly Mike at a bar and takes him to local doctor Cody, noticing symptoms that suggest Mike has become a vampire. After witnessing Danny fly into his house, Matt flees and informs Ben, Susan, Cody, and Sheriff Parkins Gillespie. They examine Mike's now-lifeless body, and later that night, Mike fully turns into a vampire, but Matt wards him off with a cross. Danny tries to trick his friend Mark Petrie into letting him in, but Mark resists and fends off Danny. The next day, Cody learns that Danny's mother has been found dead.
Cody confronts Matt about the vampires, and he explains how to defeat them. Mark and Matt break into the Marsten House to kill Barlow, but Straker traps them in the basement where Barlow bites Matt. Straker kidnaps Mark while Ben, Susan, and Cody investigate Danny's mother's corpse at the morgue. She turns and bites Cody before being killed with a cross, but Cody stops herself from turning with a rabies shot. Barlow's vampire minions attack the town, turning several residents. The next day, Mark escapes and kills Straker. Ben, Susan, and Cody seek advice from Father Callahan. Mark informs them about Barlow, and they investigate the Marsten House, where they are attacked by a turned Matt. Ben kills him with a wooden stake.
As vampires overrun the town, Sheriff Gillespie attempts to flee but is killed. Susan and Ben try to warn Susan's mother, who reveals she is Barlow's human servant, and Susan is bitten. Father Callahan tries to warn Mark's parents, but Barlow arrives and kills them. Barlow kills Callahan while Mark takes shelter in his tree house. Ben takes Susan to the church, which is protected from vampires. Cody cannot cure her, and Susan fully turns before fleeing. Ben chases her but is attacked by turned residents and seeks refuge in the church again.
Mark searches for Barlow and breaks into Straker's shop, killing Danny. Ben and Cody find Mark and realize the vampires are hiding at the local drive-in theater. As they prepare to kill Susan, Cody is shot by Susan's mother. The sun sets, and vampires attack Ben while Mark kills Susan's mother, exposing the vampires to sunlight and destroying them. Barlow emerges and attacks Mark, but Ben kills Susan and saves Mark, finally killing Barlow with a stake. Ben and Mark drive off, leaving the destroyed town behind.
