 The story begins with the Hardy Boys rescuing a boy from a road hog who looks suspiciously like a zombie wearing a Hessian uniform.The boy turns out to be Rolf Allen, who wants the Hardys to investigate a string of forest fires in Vermont, and the number one suspect is the zombie in the Hessian uniform.Shortly later, the Hardys are approached by a circus owner named Tariski, who needs their help in finding out the culprit who is sabotaging his circus.