Two construction engineers are between more than just a rock and a hard place when one of them discovers the other's violent past during an explosive tunnel blast.
Bret and Bart's devotion to one another is tested when they're offered a deal that can mean $10,000 for one of them, but just one.
Rollins and Wyatt have discovered a cure for gill fever. As they plan to market the product, they find that Jack Huxley has bought the aquarium business and owns all patents and intellectual property. Huxley is murdered; Wyatt is charged.
A man's house is burned and his livestock killed, but he refuses to identify the perpetrators to the marshal.
It is time to send the tax money to the governor, and Sergeant Garcia has a plan to thwart any attempt to steal the funds during the long journey. He orders the town blacksmith to build a huge iron box that requires a special key to open it. The money will be placed in the box and the key sent to the governor by a separate route.
Frank Blandon, a man with only one good arm, wanders on to the ranch. Lucas gave Blandon a job to ""hire him and Mark a clear conscience"". General Sheridan and his patrol wandered by and Lucas offered to let them stay the night at the ranch. Blandon pulled a gun on General Sheridan, as it turned out Blandon was a confederate soldier, who once had General Sheridan in his gun sight during the war. Blandon hung fire, but Sheridan did not hesitate and blew out Blandon's shoulder. General Sheridan shamed Blandon out of exacting his revenge, then lifted Blandon's spirit by praising Johnny Rebs' fighting spirit. Sheridan ordered that Blandon be taken to a hospital to have his shoulder properly mended, carrying out his Commander in Chief's last order to ""Bind up the Nation's wounds.""
Following the drilling attempt, a hole has somehow opened up in the wall which allows Quatermass and the others access to the interior chamber. There they find the remains of insect-like aliens resembling giant three-legged locusts, with stubby antennae on their heads giving the impression of horns. As Quatermass and Roney examine the remains, they theorise that the aliens might have come from a nearby planet which was habitable five million years ago — Mars.
Motherly love knows no bounds when a woman decides to get revenge on the married man who has been dating her daughter.
Bret, seeking buried Confederate treasure in Elwood, Kansas, keeps running afoul of U.S. Marshal Mort Dooley. The marshal keeps running Bret out of town. Bret, in turn, keeps outwitting the lawman.
Eva Martell is hired out of numerous candidates by Melvin Slater to impersonate a woman named Helen Reynolds. Eva is paid extremely well and given a nice apartment to live in with her Aunt Agnes as long as she continues with her impersonation. Both Eva and her aunt suspect a rat and seek Perry's advice. Then Melvin Slater turns up dead in the apartment.
Matt goes along with a hoax when Chester's aging Uncle Wesley arrives for a visit. Wesley thinks Chester is the marshal and Dillion is his assistant.
Two indentured servants who wish to marry find that the law states they must have the permission of their masters. Buena, who works in the de la Vega hacienda, is told she is free to marry, but her boyfriend, Romaldo, is not so fortunate. One of his co-workers also wants to marry Buena so he convinces their boss that Romaldo plans to run away after the ceremony.
Ward Haskins guns down Joe Flecker, who has evidence that could be used to blackmail him. Haskins thinks the information was given to Lucas, since he brought Flecker to the doctor before he died. Stirred up by Haskins behavior, Lucas goes through Flecker's things, finding a wanted poster for Haskins in the sole of Flecker's boot. He also finds Doc Burrage drinking. Doc is discouraged because three children have died of an anthrax epidemic that he has the new serum for, but nobody is willing to allow him to administer it in time. Haskins rides out to the ranch and is bitten by Flecker's horse, which is now believed to have anthrax. Mark overhears about how anthrax always causes death and is worried because he had bitten by Flecker's horse, also.
The shell of the object is so hard that even a borazon drill makes no impression, and when the attempt is made, strange vibrations cause severe distress in the people around the object. Quatermass interviews the local residents and discovers that sightings of ghosts and other poltergeist activity have been common in the area for decades. Meanwhile, a soldier is carried out of the object in hysterics — he claims to have seen a dwarf-like apparition walk through the wall of the artefact, a description which matches a 1927 newspaper account of a ghost sighting. Following the drilling attempt, a hole has somehow opened up in the wall which allows Quatermass and the others access to the interior chamber.
A funeral parlor owner is put in an awkward position when a deceased client comes back to life and demands a much smaller affair than what was planned for his funeral.
Bret and Bart are pursuing the same woman. What's the attraction? The $10,000 she copped from them.
Sarah Werner asks Perry to find her husband, Hugo Werner, who ran off with her inheritance. Hugo, now using the name Hans Breel, is now working on a gem scam but his scheme backfires when he is murdered and Sarah is charged with the crime.
Over the objections of his sometime partner Rod Allison, treacherous Jim Box murders aging rancher Jesse Wheat, then attempts to steal cattle from Wheat's young widow.
Ricardo leaves town but causes another problem for Diego before he goes. Still infatuated with Anna Maria, Ricardo tells her that Zorro would unmask himself if he really loved her. The problem is, Diego does love her, and thus begins to consider turning himself in. The governor offers the outlaw amnesty if he will surrender himself at a public ceremony.
Rumson, without even saying to whom he had sold his property, left the bill of sale with the bank and moved away from North Fork. Curge, who's highest offer was upped by $1,000.00 is upset because Rumson sold out to a ""peppergut"". The Argentez family who bought the place are from Argentina. Lucas arranges for Mark to hang out with Manolo, who teaches Mark to use the Bolas. Manolo is angered at anyone who shows interest in his sister, he believes she is only for a ""Caballero"". Her latest suitor, Ned Dunnell, has been found murdered and the townsfolk are quick to believe it was Manolo.