Soon after Hoppy and Red arrive where the murderous outlaws operate with impunity and precision in lawless Canyon City to help sheriff Barnett the mark of the vigilante, 3-7-77, starts to appear at the locations of those Hoppy suspects.
The Army sends Hoppy to Arizona Territory to investigate raids on a telegraphic construction project and, after the project leader is killed, uncovers a conspiracy led by the holder of the area trading post enterprise to stop the telegraph.
Drunk Picture Pete has photographed a on reservation hill has rich in copper ore of which speculator Rush has learned and has, to get the ore land, made it appear by killing and property destruction that the Apache and Maricopa are at war.
Jim Adams convicted convincingly of Ben Samuels murder has escaped from prison and, while Hoppy protects Adams from vigilantism, Hoppy is troubled by an Adams trial physical description and huge doctor fees paid by Samuels brother.
An exhausted boy arrives at the Bar 20 with a tale of his father s disappearance and, although Hoppy presumes the father is dead, goes to the boy s home where evidence of the father s presence unnerves a stepmother and a housekeeper.
When Ted Gray is attacked by Martinez for lying about receipt of mortgage money, his uncle Ollie states he will foreclose and then Ollie is found murdered with several pieces of clear evidence against Martinez but Hoppy is skeptical of it.
An indebted lawyer fakes a stage holdup with the murder of the driver and a client to gain the client s fortune and blame the cavalry nephew in a clothing switch with an accomplice and nephew who left for dead survives but loses memory.
Hoppy s mission from a law & order committee to prevent a town boss from blocking a territorial charter vote is imperiled when Hoppy s recently arrived lawyer nephew agrees to defend a boss henchman and a victim changes his story.
As Twin Rivers becomes no longer a quiet cattle town due to a gold strike, two partners of Bummer Lowe, who Red and others have grub-staked to look for gold, have been killed and then Bummer continues to ail unresponsive to medication.
Hoppy is asked by immigration to investigate Chinese illegal aliens crossed from Mexico and left in the desert to die and finds a message in the sand beside a deceased implicating a Chinese speaking white man with a limp
Outlaws telegram Samuel Harron s sister Matilda that he is ill and needs her so the outlaws can kidnap her to ransom Harron s testimony and when the sheriff will not help after Hoppy rescues Matilda, Red masquerades as her to set a trap.
Thieves steal gold coins meant for a relief fund and make them into gold nuggets that they use an old prospector to launder which throws suspicion on the prospector s granddaughter s assayer husband.
Jason Rand who acquires area homesteads by shady means marries Trixie Brown who blackmails him about proof she has on murder so she can not testify against him but Trixie has written down facts and secreted the document.
Bricker, Jim Taggart s rep, reports that Taggart s nephew has been killed by robbers that stole a railroad survey but actually Bricker has killed the nephew to deliver the plans for a fee to Taggart s rival so Taggart loses the contract.
Hoppy is assigned to perform the extradition of Marco Rodriquez who appears framed for murder while on the way to investigate the smuggling of cattle from a diseased border area of Mexico and discovers the tasks are related.