Railroad Detective Matt Clark (Jim Davis) and his assistant Frankie Adams (Mary Castle), investigate the stealing of a herd of horses belonging to the U. S. Cavalry. They learn that the leader of the outlaws is a woman named Belle Starr (Marie Windsor).
In the second entry of this Emmy-award winning series, all filled with archive footage from Republic Pictures theatrical features, railroad detective Matt Clark (Jim Davis), and his assistant Frankie Adams (Mary Castle), set out on the trail of a gang of cattle rustlers led by one of the West's youngest and most notorious outlaws, Billy Bonney (Richard Jaeckel), aka Billy the Kid.
Railroad detectives Matt Clark (Jim Davis)and Frankie Adams (Mary Castle), with the aid of much stock footage from earlier Republic Pictures films, pursue the vengeful James brothers, Frank (Richard Travis) and Jesse (Lee Van Cleef), who declare war on the law after their young half-brother is killed in a police ambush.
Railroad detectives Matt Clark (Jim Davis) and Frankie Adams (Mary Castle), go after Apache chief Geronimo (Chief Yowlachie), who has been identified by Joe Burns (Emile Meyer), the night watchman of the railroad yards, as the leader of a band of freight-car robbers.
Detectives Matt and Frankie are asked by Colonel Marsham to infiltrate the vicious Quantrill gang. They do so on the eve of the Lawrence Kansas massacre that they are unable to prevent. Matt vows to track down Quantrill personally.
Matt and Frankie head to Sweetwater, Wyoming where major cattle ranches are suffering heavy losses. A woman nicknamed Cattle Kate becomes the focus due the number of livestock she sells despite her small operation. A grim fate awaits her and her associate.
After the Sam Bass gang steals sixty thousand dollar of gold coin from a train on which Frankie rides, Frankie pretends to be a waitress romantically interested in captured henchman Hayes to get Hayes to reveal Bass' location.
Railroad detective Matt Clark learns of Johnny Ringo while investigating a train robbery. Frankie gets a job allowing her to some undercover work. Matt meets Johnny, a noted gunslinger, trailing him to a desert showdown.
Matt and Frankie head to Coffeyville in 1892 when they hear that the Dalton brothers and their gang are planning something big. They arrive in time to thwart the double bank robbery with the help of the stalwart citizens of the town.
Matt and Frankie head to Tombstone, Arizona to track down Doc Holliday who they suspect is involved with the Clanton gang. While there they meet famed sheriff Wyatt Earp and become part of the gunfight at OK Corral.
The Younger Brothers believe their past with the Quantrill Raiders keeps them from living an honest life and start planning a daring bank robbery in Minnesota. Matt Clark, with a little help from Frankie, ensures that it doesn't end well.
John Wesley Hardin, the infamous killer, is herding cattle to Abilene when he shoots two Indians in cold blood. Detectives Matt and Frankie arrive in Kansas to bring him to justice. Hardin's time in prison, rehabilitation, and final gunfight are recounted.
The 1850's California gold fields is home to notorious bandit and killer Joaquin Murietta. Matt and Frankie arrive to track him down but he kidnaps Frankie, believing she owns his hacienda. Matt and Captain Love trail Murietta to the bitter end.
Tiburcio Vasquez vows vengeance against Anglos after his sister Dolores is killed. Matt and Frankie try to stop his years of terror in Southern California after a railroad agent is killed with the help of the local padre.
Black Bart is responsible for a string of stage coach robberies but he has proved elusive to company detectives Matt and Frankie. Bob arrives from the city to help but it is the youngster Todd that provides the key to the case.
Plummer is the sheriff of Bannock, Montana in the 1860's but runs a criminal gang as a source of wealth. When another stage is robbed Matt and Frankie arrive to find out who is behind the crime spree responsible for the deaths of so many.
After Longley and Kelso escape from a chain gang, Matt goes to a circus where Longley's girlfriend Mamie works while Kelso comes to get Mamie but mistakenly takes Frankie so that Longley must come himself and Matt follows to recover loot.
As the end of the 19th century, a murdering desperado Harry Tracy terrorizes America's northwest. Matt and Frankie head to the area after a train is stolen with Frankie going undercover. Soon Matt and a posse have the outlaw cornered.
Butch Cassidy is presented as a jovial type against killing as the leader of the notorious Wild Bunch. Matt and Frankie go after the outlaws when bank notes appear with phony signatures, trailing Butch all the way to South America.
After a robbery by the Doolin gang, Matt interviews a mortally wounded Ed Brinkley regarding the location of the Doolin hideout in Oklahoma. Frankie shows up pretending to be Ed's widow but the actual wife appears complicating matters. An ambush helps bring the Doolins to justice.
Black Jack Ketchum is a wanted outlaw in two countries leading him to lie low at the Cullen Ranch in 1890's New Mexico. Matt and Frankie head to the area to stop the gang's activities and save young Eddie Cullen from a hangman's noose.
Matt and Frankie stop in to see Matt's old friend Tom Horn while investigating a dispute involving cattle in Wyoming. When a young homesteader is killed the two detectives begin to see evidence adding up against Horn. Matt is shaken by his friend's betrayal.
Matt and Frankie arrive in Austin in the 1880's to investigate the background of Ben Thompson. Matt gets employment at a gambling den owned by Ben's ex Texas where he starts to build a case establishing Ben's criminal activities.
During a robbery Frankie is shot as she pulls the mask off her assailant. Matt arrests John Allison, after Frankie's life is endangered when her doctor is kidnapped. An enraged Clay, known for his willingness to kill, falls into Matt's trap.