Much of this book takes place in Blythe, California and it cites real, current locales, such as Hobson Way and the giant intaglios north of Blythe on U.S. Highway 95. [1] In the end, the boys discover that Grafton's fellow explorer had a part in the gang of criminal's racket. With this, Grafton is rescued, and the thugs who apparently were smuggling illegal checks across the border are caught.