Plot summary (original edition)

Frank and Joe travel with their detective father, Fenton Hardy, to a town two hours from Bayport to break up a truck hijacking ring and recover two stolen swords for wealthy shipping magnate Arthur Barker.

Plot summary (revised edition)

After their fencing instructor Ettore Russo tells them about a family sword, the championship saber Adalante, the Hardy Boys go to California to search for the sword's missing half. Supposedly written on the sword is the owner's will that names the fencing instructor as a major heir of his deceased grandfather's fortune. Others also intent on finding the sword try hard to foil the Hardys from getting there first.

Original edition (1942)

• Ghostwriter: John Button
• Summary: The boys solve a series of truck thefts and locate Arthur Barker's stolen swords.

Revised edition (1969)

• Revision type: Completely rewritten; some plot elements are retained, but the new story involves a gang of bank robbers who are searching for the missing half of a sword belonging to the family of the Hardy Boys' fencing instructor.
• Ghostwriter: Richard Deming