This story has been published under three separate titles, as part of three different series. As Airplane Boys on the Border Line, it is the first entry in The Airplane Boys series; as The Border-Line Mystery (published under the pseudonym M. Delmore Marquith) it is the first entry in the Skylarking Comrades series; and as The Air Mystery of Isle La Motte, it is the first entry in The Sky Buddies Series.
The Airplane Boys series by E. J. Craine (originally published in the 1930s) is a new series of hair-raising sky adventures. The dare-devil younger generation of this day and age, going through stunts, flying day and night, having their own fun and at the same time helping others. The technical end of aviation is also brought in, and the humorous situations keep the reader amused constantly.
Teenage stepbrothers, with their own plane, fly up to Vermont near the Canadian border to visit their aunt and uncle who raise turkeys. They soon are involved in three mysteries: helping the Canadian police stop smugglers crossing the border, trying to stop the theft of a large portion of their uncle's turkeys, and figuring out the mysterious boy and his uncle who are helping out on the farm. Of course there are other adventures of helping an airmail pilot deliver his important cargo and helping rescue people during a dangerous flood.
Plenty of adventure. A fun book to read. I love it when someone of another race says that Americans are clearly inferior. Turns around the typical stereotype and prejudice.