The narrative follows the Hardy boys, Frank and Joe, as they navigate a series of thrilling adventures involving their friends Chet Morton and Biff Hooper. The story begins with the boys preparing for a summer trip, but their plans are interrupted when they learn that their father, Fenton Hardy, is pursuing a notorious criminal known as Baldy Turk. As Frank and Joe remain in Bayport, Chet and Biff embark on their motorboat trip, but they soon encounter danger when they are pursued by a mysterious motorboat. The boys manage to escape, but Chet and Biff are later kidnapped by the gang, who mistake them for the Hardy boys. The gang's plan is to hold them for ransom, leveraging Fenton Hardy's reputation as a detective. The Hardy boys, concerned for their friends, set out to find them, leading to a series of investigations that take them to Blacksnake Island. They discover the gang's hideout and learn that their father has also been captured. The boys devise a plan to rescue Chet and Biff, culminating in a daring escape from the gang's cave. With the help of a revenue cutter, the Hardy boys manage to capture the gangsters and free their friends. The story concludes with a triumphant return to Bayport, where the boys are celebrated as heroes. However, the adventure leaves them with lingering concerns about their father's safety, setting the stage for future escapades.
By Franklin W. Dixon · First published 1927 · Genre: Mystery, Adventure, Young Adult · 23 chapters