3. BOB DEXTER AND THE STORM MOUNTAIN MYSTERY or The Secret of the Log Cabin
Bob Dexter came upon a man mysteriously injured and befriended him,
which led Bob into the midst of a series of strange events.
4. BOB DEXTER AND THE AEROPLANE MYSTERY or The Secret of the Jint San
Bob and his chums witness the mysterious disappearance of an aeroplane
and find excitement in their exploration of an unknown cave.
5. BOB DEXTER AND THE SEAPLANE MYSTERY or The Secret of the White Stones
Bob Dexter, while on a vacation, captures a band of criminals, and solves
a mystery in which millions of dollars in gems and jewelry had been stolen.
6. BOB DEXTER AND THE RED AUTO MYSTERY or The Secret of the Flying Car
A story of a mysterious red auto is packed with many hair-raising adventures.
Bob comes to the rescue and captures the criminals.
7. BOB DEXTER AND THE RADIO MYSTERY or The Secret of the Counterfeiters
When Bob and his chums resolve to clear up a baffling mystery they do
it with many narrow escapes.