Lewis Barnavelt is in trouble again! This time he has stumbled upon something more powerful than even his overactive imagination can dream up. On camping trip with his Scout troop, Lewis discovers an ancient whistle and a strange grave. He quickly realizes that this whistle has the magic ability to get rid of the bullies who insist on making his life miserable. What Lewis doesn't know is that the whistle also has a more sinister power: It summons up an ancient vampire!

With the help of his best friend, Rose Rita, and his uncle Jonathan, and their next-door neighbor, Mrs. Zimmermann, Lewis must fight the female blood-sucker that threatens his own life and the lives of those he loves.