From End of Casefile#7: Callie Shaw has had it with the Hardys! Frank's girlfriend wants to know why she can't work with them. She's just as good an investigator as they are. Storming home after an argument, she literally walks into an ambush -- and a deadly test of her detective abilities. As more and more mysterious attacks are aimed at Callie, one thing becomes clear. This case had better be solved before she gets killed! With the help of a beautiful young investigative reporter,the Hardys tackle one of the strangest cases of their career. Will they find the mysterious attacker? Can they save Callie? Or are they in too deep even to save themselves?

From back cover: Frank Hardy's girlfriend Callie Shaw is determined to join him and Joe in solving crimes. So when she bumps into a mailman and mistakenly recovers a top-secret codebook, Callie thinks she's found the perfect case. She challenges the brother detectives to help her break the code. Trouble is, the real owner is deadly serious about getting it back. Joe is knocked cold during a daring burglary, and when he comes to, the black book is missing. But not before Frank has uncovered a link to a secret network of fraud, corruption, and murder. It seems Callie has stumbled on to a major scandal -- Will Frank and Joe end up taking the fall?