A sleek new hydrofoil is scheduled to start ferrying passengers between Bayport and Cape Cutlass.
Startling developments plunge the teenage detectives into a dangerous chase by sea, air, and land in pursuit of a gang of hardened criminals who operate by the signs of the Zodia.
Fearing sabotage, he begs Frank and Joe Hardy to guard the Flying Express on her maiden trip.
But business enemies of the hydrofoil owner have stirred up a hornets\' nest of violent opposition among small boat owners.
A sleek new hydrofoil is scheduled to start ferrying passengers between Bayport and Cape Cutlass