96 pages! Frank and Joe Hardy finish up a case helping a fellow ATAC (American Teens Against Crime) agent, who sharp-eyed fans may recognize despite her Alias. Things seem to quiet down when ATAC sends Frank and Joe undercover to investigate a new Mall opening in Bayport, due to several suspicious accidents there. But things get exciting when the night before the big opening, Joe, Frank, and seven others are mysteriously locked in the mall - with a murderer on the loose.