The Secret of Skull Mountain

Running on Empty (Hardy Boys Casefiles #36)

The Twin Dilemma

Danger Overseas (Nancy Drew: Girl Detective and Hardy Boys: Undercover Brothers Super Mystery #2)

The Mystery of the Coughing Dragon

Voice In The Suitcase #8 (Judy Bolton)

Mystery at Dead End Farm

Secret Seven on the Trail

The Hardy Boys

Frank and Joe Hardy, after being tipped off by their father, international detective Fenton Hardy, follow a trail of clues that lead them to Mexico. They must solve the mystery behind the mark on a particular door to thwart an international plot.

Discover Your Child's Next Read

The Secret of Skull Mountain

Franklin W. Dixon, 1948

Running on Empty (Hardy Boys Casefiles #36)

Franklin W. Dixon, 1993

The Twin Dilemma

Franklin W. Dixon, Carolyn Keene, 1993

Danger Overseas (Nancy Drew: Girl Detective and Hardy Boys: Undercover Brothers Super Mystery #2)

Franklin W. Dixon, Carolyn Keene, 2008

The Mystery of the Coughing Dragon

Nick West, Robert Arthur, 1970

Voice In The Suitcase #8 (Judy Bolton)

Margaret Sutton, Pelagie Doane, 1935

Mystery at Dead End Farm

Mary C. Jane, 1978

Secret Seven on the Trail

Enid Blyton, 1993