When their peregrine falcon brings down a homing pigeon carrying rubies, the Hardy brothers find themselves involved with kidnappers.

A banker who has been receiving threatening notes enlists the help of the Hardy boys. Before very long, the young sleuths find themselves entangled in the investigation of a notorious band of thieves.

While on Christmas vacation, the Hardy boys find themselves in two mysteries. One is the disappearance of the grandson of their host, and the other is the theft of a collection of antique medals. The investigation pits them against a ghostly prowler and mysterious strangers.

Frank and Joe have gone hunting--but instead of sniffing out wildlife, they're out to find the Wilkerson family.

The Hardy boys investigate when a friend's plane is stolen at an air show, an event which triggers a crime wave.

Joe and Frank go looking for the Blackstone fortune. They come upon a sea monster, are knocked out by a thug, and are taken hostage.

The Hardy boys dial a wrong number, get the Pentagon, and suddenly find themselves in a dangerous adventure involving national security.

Frank and Joe try to find the criminals who are sabotaging a motorcycle exhibition.

When they journey to Alaska to help a friend who feels his life is in danger, the Hardy brothers find their own lives threatened.