Toby Michaels and his father are monster fanatics and Toby's room is full of monster movie memorabilia. When a new neighbor moves in, Toby goes next door to see if there are any children to play with. He meets the neighbor, Emile Bendictson, who notices Toby's monster interest and his vast collection through the window. In the course of the conversation, Emile reveals that he is a vampire, but Toby does not believe him because Emile is outside and it is still daylight. Emile just laughs it off, but Toby goes home to tell his tale to his parents. They, of course, dismiss it too.

Toby decides to spy on Emile, who has enough strength to lift the front end of his car while polishing it. Toby gets caught by Emile and tries to protect himself with garlic and a crucifix. Emile laughs and tells him that most of what he has read about vampires is not accurate. To illustrate this, Emile treats the boy to a garlic-filled Italian dinner. Emile tells Toby he wishes to just live out the rest of his days. Later, Toby goes to Emile's house and finds hospital bags of blood in the bottom of a closet. Then Toby begins to get sick, which his parents think is a case of the flu.

Emile comes to Toby's window and invites him to go for a walk. They go to the cemetery and Emile explains how vampires really are. They are like people who are infected with a thirst. Toby doesn't quite understand, but Emile also explains that after he changed he had to move constantly. He says that the presence of vampires incites a genetic mutation in average humans. He pulls Toby closer and Toby sneezes incessantly to illustrate his point. Humans have a genetic aversion to "his kind", as he puts it; Emile can't stay in one place too long, otherwise nearby humans will mutate and kill him. But before they go, Emile shows Toby a gift: how to enjoy lightning bugs in the cornfield. It was something he learned as a boy.

Toby becomes even sicker and so do his parents. It turns out all the neighbors in a five block radius are becoming ill. After midnight, Toby and his parents begin to change, mutating into the monsters Emile described. Emile seems to know that his end is coming; he leaves his front door open and is killed by a pack of monsters that enter his house. The next morning, Emile's battered body is being loaded into an ambulance. The neighbors all mourn his passing, not realizing that it was they who killed him. That night, Toby takes his dad and shows him the lightning bugs in the field, and his dad sneezes.

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