The Secret of the Island Treasure

The Twin Dilemma

Running on Empty (Hardy Boys Casefiles #36)

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

Britfield & The Rise of the Lion

The Hayley Mysteries: The Missing Jewels (The Hayley Mysteries, 2)

The Mystery of the Cranky Collector

The Case of the July 4th Jinx (Milo and Jazz Mysteries)

The Hardy Boys

In The Secret of the Caves, the Hardys face a trio of rogues. While investigating a string of false clues, the Hardy boys, along with their friend Chet, are able to solve the mystery and reunite a long-lost family member with their rightful inheritance.

Discover Your Child's Next Read

The Secret of the Island Treasure

Franklin W. Dixon, 1990

The Twin Dilemma

Franklin W. Dixon, Carolyn Keene, 1993

Running on Empty (Hardy Boys Casefiles #36)

Franklin W. Dixon, 1993

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

Franklin W. Dixon, Carolyn Keene, 2008

Britfield & The Rise of the Lion

C.R. Stewart, 2021

The Hayley Mysteries: The Missing Jewels (The Hayley Mysteries, 2)

Hayley LeBlanc, 2022

The Mystery of the Cranky Collector

M. V. Carey, Mary Carey, 1987

The Case of the July 4th Jinx (Milo and Jazz Mysteries)

Amy Wummer, Lewis B. Montgomery, Mara Rockliff, 2010