The Secret of Skull Mountain

The Hardy Boys Secret Files Collection Books 1-5

The Twin Dilemma

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

The Gross Ghost Mystery (Frank and Joe Hardy: The Clues Brothers #1)

The Mystery of the Coughing Dragon

Nancy Drew Starter Set - Books 1-5

Legend of the Star Runner: A Timmi Tobbson Adventure

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

The Hardy Boys Secret Files Collection Books 1-5

Franklin W. Dixon, Scott Burroughs, 2014

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 Gross Ghost Mystery (Frank and Joe Hardy: The Clues Brothers #1)

Franklin W. Dixon, 1997

The Mystery of the Coughing Dragon

Nick West, Robert Arthur, 1970

Nancy Drew Starter Set - Books 1-5

Carolyn Keene, 1930

Legend of the Star Runner: A Timmi Tobbson Adventure

J Wagner, 2018