In this violent entry, a lady banker murders all the ranchers in oil-rich Lost Valley in order to gain control of the property. She is planning to murder eight-year-old Jamie Jenkins when Roy intervenes.
Mike and Betty Tobin are frightened children left alone in a cabin while their fur-trapping father is held captive by outlaws after his valuable pelts.
Parson Loomis, carrying a payroll from the Mineral City Bank to the Hardrock Mine, is ambushed by two thieves, one of whom later disguises himself as the visiting ""Reverend Brown,"" a supposed friend of Loomis's. Roy, Dale, Pat, and the parson's childern soon realize that their ""guest"" is no man of the cloth.
A swift, mysterious desperado called The Larabee Kid has been hijacking stolen loot from thieves who prey on stagecoaches. As it develops, he is actually the son of a slain marshal, seeking vengeance on the outlaws who murdered his father.
Beaver Jones, president of the Paradise Valley Fur Traders Association, is defrauded by his grandson Tim, who is hijacking furs in order to pay off a gambling debt.
The Hard Luck Insurance Company, for one flat premium payment, will insure any rancher for the rest of his life-or so the firm contends. Roy reveals that the entire affair is a ruthless racket.
When the offices of the law are turned over to students in honor of Boy's Day, Bob Miner is named sheriff and his unscrupulous uncle takes advantage of the opportunity to acquire adjoining land from an elderly rancher.
Roy and Dale are caught between the fight of cattlemen and homesteaders who want the same land for different reasons.
Lanny Gaines, a teenager with artistic talent, moves with his father to Paradise Valley, but they are dismayed when no one pays them a welcome call. When three desperados posing as surveyors ask Gaines for lodging, the old man is only too glad to comply.
When the Castle gang hears Roy and Dale say ""The Key to the greatest treasure in the world is in that book,"" they resort to violence to gain possession of it.
When they are unable to find work, two youths turn to crime, even endangering a kindly old couple who befriended them.
Pat Brady and Nellybelle are kidnapped by a gang of outlaws, one of whom coincidentally may be inheriting a million dollars.
Roy and Dale are suspicious of a local school teacher's growing nervousness after the Paradise Valley stage is robbed.
There is a large reward for the capture of desperado Curt Carlson. A Young man sees the poster and decides to run away from his overbearing father to join the Carlson gang.
Dale befriends a little girl called ""Johnnie,"" whose outlaw father has been murdered by his confederates.
Marv Hanley is a quick-tempered, trigger-happy sheep rancher whose brother-in-law, Dunc Wright, has recently held up a stage. Marv, who has never had any use for Dunc, joins the posse in order to gun him down.
Roy, Dale, and Pat are visiting nearby Carson County. While there, they meet a little girl named Janie Howard whose beloved horse has been stolen by an outlaw who has framed Janie's father in a robbery.
Ellen Corbin, a waitress at the Eureka Cafe, is awaiting her father's release from prison. As soon as Corbin returns to Mineral City, his former partner begins to menace him.