The Hardy boys were sons of a celebrated American dectective and from their father learned the particulars of a number of unusual crimes. They were fired with zeal to bring the criminals to justice, and during their hours from school, and during their vacation days, they followed up clues they unearthed themselves — aiding their parent very materially. Stories which are absorbing in the extreme.

Chet and Biff, two of the Hardy Boys' chums, are missing. It turns out that they have been kidnapped after being mistaken for Frank and Joe. The remaining group of school chums set to work to discover their whereabouts; the brothers finally finding them on an abandoned island mainly inhabited by black snakes. One adventure after another beset our intrepid pair as they work at rescuing their friends from a members of a gang.