When A.T.A.C. agents across the country start getting strange and bizarre cases, it's up to Joe and Frank Hardy to find the computer hacker responsible! Anyone smart enough to break into A.T.A.C. security certainly has the skills to make things difficult for the Hardy Boys - even in what seems to be the empty Bayport High School in the middle of the night. But even the Undercover Brothers will be surprised when they uncover their adversary's true identity! With cameos by Lindsay Rider, the Sisters Noir, and Dennis Hogan, this special case involves a list of suspects that includes almost everyone the Hardy Boys have ever met!