Popular horror writer Richard Kinnell attends a book signing where he's greeted by dozens of clamoring and eccentric fans. Afterward he goes to his doctor and is informed that he has cancer.
As Kinnell drives for home and stops for gas, he sees a nearby yard sale and decides to visit it. One picture catches his eye, a rendering of a maniac driving a car. The woman running the sale, Judy, recognizes him and tells about how the painting belonged to a Bobby Hastings, who drew the picture before he killed himself. That painting is the only one let--Bobby burned the rest. When he died he pinned a note on his chest saying, "I can't stand what's happening to me."
Judy sells the painting to him for $45 and then Kinnell stops off to visit his Aunt Trudy. He shows her the painting and notices the name on the back--"The Road Virus Heads North." He also notices a tattoo on the guy's arm, a tattoo he didn't see before. Over coffee, Kinnell reveals he has cancer and needs to take more tests. As he leaves, she advises him to take it easy, find a girl, and throw the painting away.
Back at the sale, Judy is picking up when a figure comes up behind her and brutally stabs her to death. There's the sound of an engine as the figure gets into the car, leaving her severed head behind.
While driving along, Kinnell glances at the painting and, distracted, goes off the road into a puddle and then keeps on going. He loses his muffler and stops off to check, and notices the painting glass is cracked. He also now sees a church in the background, the church that he saw near the yard sale. Scared, Kinnell throws the painting into a stream.
Next on his way home Kinnell stops off at his friend Sally, who's keeping his dog. When she looks in the car she sees the painting, now back in the car, and it's changed to show the yard sale with the killer out of the car and decapitating Judy.
Kinnell tries to explain to Sally what's going on and she thinks he's drinking or taking drugs. He reveals he got the check-up information but is more concerned he's losing his mind. She suggests she give him a healing and they go out to her sweat lodge, missing the newscast confirming Judy's death.
Sally applies crystals and herbal remedies, and Kinnell goes to sleep and hallucinates the car and its driver getting closer while he smashes the painting. He wakes up and prepares to leave and finds Sally has disposed of the painting. Concerned for her safety, he gives her money to stay at a hotel and then leaves.
Kinnell pulls up to his home and takes a shower and hallucinates seeing the car outside. He goes to the car and opens it, and gets in confronts the killer, asserting it's really the virus in his body. He tells the killer that if he does then the killer dies, but the killer says he's Kinnell's fear. Kinnell tries to get out but the door is locked and then the killer disappears…only to come at him from the rear.
Kinnell wakes up from his dream and turns on the news, to hear about Judy's death and figures it's real rather than a dream. Worse, the painting is on the wall behind him and driving by his Aunt Trudy's. He calls her but gets her answering machine, which says she's gone to a movie. The car is outside her house and drives off. Kinnell sets the painting on fire in his fireplace, seemingly destroying it.
Aunt Trudy calls a few minutes later and he reassures her the evil is destroyed. He looks outside and sees the car pull up outside the house. When he looks away for a second, he sees the painting on the wall, showing the killer entering the house. Kinnell looks down to see the killer come in, and his dog attacks it. There's the sound of a knife and then no more sound from the dog. Kinnell throws the painting down the stairs but the killer ignores it and comes up the stairs.
Kinnell looks for a way out without success as the killer gets closer. Kinnell back, trips over some books, and falls down the stairs to land on the painting. Looking at the picture, Kinnell sees blood in the car and looks up to see the killer just outside. The killer gestures for him to come out and get in the car. Giving in to the inevitable, Kinnell starts to walk outside to his fate.