The Happy Hollisters and the Cowboy Mystery

"Domingo" the burro the Hollisters were given for a pet the last time they were out West is the innocent means by which the Hollisters once again find themselves following the mystery trail on horseback. Because of a near accident the Hollister children meet and befriend the Blairs who are from Nevada. They learn that Mr. Blair is trying to sell some of his property on the Tumbling K Ranch, but strange and eerie events have discouraged prospective buyers. Naturally, the minute the Hollisters hear mystery is involved they are eager to be in the thick of it. Their interest is further aroused when a prowler is discovered spying on them in Shoreham.