Erskine and Colby pursue a pair of bank robbers from Philadelphia to Oregon. The criminals, Perry and Shep, are an odd mix of urban and rural backgrounds. Perry plans the robberies while Shep (a "redneck" as Perry calls him) specializes in gun play. Their eventual target is the payroll of a tunnel construction project in Oregon. Along the way, Shep is drawn to a woman, who tries to play the criminals off each other. Shep also is a bit of ticking bomb. The FBI agents try to catch the criminals before fatalities occur.
A Boston company that is developing a new type of laser is the target of a spy ring. One compromised employee is injured at a cheap hotel when the elevator cable snaps. Erskine and Colby are assigned to protect the project. Meanwhile, the spy ring is targeting another employee, who is deep in debt, to entice him to provide the information the ring needs.
A man working for La Cosa Nostra is on trial. The man who recruited him into the criminal organization believes he will crack during the trial and arranges for him to jump bail and flee the country. Erskine and Colby lead the FBI's pursuit; the man's testimony is needed to incriminate La Cosa Nostra members. Meanwhile, the commission of La Cosa Nostra wants the man dead and has ordered a hit. On top of all that, the fleeing man's wife, who is seven months pregnant, is with him and her condition threatens her life and her unborn child's.
Erskine and Colby lead the manhunt for escaped prisoner Arthur McBride. McBride is a genius and a ruthless, borderline psychopath and more than willing to kill to accomplish his means. The FBI men will follow a trail from Kansas to Chicago to Miami. The question is whether Erskine can corner his quarry before his next big job: robbing an armored car on its way from a race track.
The mentally unstable Walker Oborn has abducted Emily Willis. FBI Assistant Director Arthur Ward tells Erskine that "the director" has taken a special interest in the case and wants it resolved as soon as possible. Erskine and Colby spearhead the FBI's search in the Pacific Northwest to bring the captured Emily home safely.
A group of young extremists wants to start the 'Revolution'. They blow up a govt. building but an anonymous caller phones in a tip to the police. Their leader believes someone connected to the group made the call. Because govt. property is destroyed the F.B.I. is called in to investigate.
The son of a wealthy but separated, couple is kidnapped. The abductors are a couple with issues: the man is an alcoholic while the woman is near the end of her endurance in dealing with her husband. On top of all that, the kidnapped boy has become seriously sick. Erskine and Colby lead the bureau's manhunt. But, with the boy's condition worsening, the question is whether they can break the case in time.
In Los Angeles, La Cosa Nostra has mounted an effort to infiltrate businesses owned by African Americans. Erskine and Colby lead the FBI's investigation. One businessman already has been left severely beaten when the FBI men enter the case.
Erskine and Colby are on the trail of a con artist who targets lonely, wealthy women. The FBI has entered the case because the man's latest technique involved impersonating a U.S. Navy officer. The man also is suspected of killing one of his victims. As a result, the FBI men have extra incentive to apprehend the man quickly.
Erskine and Colby seek to apprehend Arthur Majors, a fugitive who is now part of a Los Angeles-based drug ring. Majors and three others shot two and seriously wounded U.S. border patrol officers in Arizona while transporting drugs. Now, Majors has gone into business for himself. The FBI is in competition with syndicate hitmen to get to Majors first. The life of a young woman, who is fascinated by Majors, is now at risk as the hitmen close in on Majors.
The economics minister of an iron curtain country has defected. His daughter Maria is touring the U.S. and the FBI must get to her before a communist spy can spirit her back to her country to be held as ransom for her father.
Kidnappers abduct a young woman, believing her to be the daughter of a millionaire. In reality, she's the daughter of a middle-class couple who had been driving the car of the intended victim. Erskine and Colby lead the FBI's investigation of the case. But the daughters of the victim don't have the means to raise the ransom. Meanwhile, the rich father of the intended kidnap victim doesn't want to provide the ransom because it would violate the principles he has lived with all his life.
An attempt to steal a top secret formula at Millard Industries in Dallas fails when only half the formula can be taken before a security guard enters the company's computer room. The CEO of the company summons the FBI and Erskine goes undercover at the firm. The son-in-law of the founder of Millard has been seduced by a Soviet Bloc agent. The executive is unaware of the Communist affiliation of his mistress. A chemist at the company has been set up as a stalking horse so the executive can continue and steal the rest of the formula.
A $1 million painting is stolen from a museum in Kansas City, Missouri. The thieves initially plan to sell it to a collector in Europe. But when that buyer dies in an accident, they instead seek to sell it back to the museum. Inspector Erskine poses an art expert who the thieves will call upon to confirm the painting is genuine. But what Erskine doesn't know is that he arrested one of the thieves, who has been working in the museum as a volunteer, eight years earlier.
Three men attempt to kidnap a doctor vacationing in the mountains of Washington state. The doctor falls down a steep hill side. One of the three kidnappers is tracking the doctor while the other two proceed with plans to extort $200,000 from his wife. The FBI gets a break when one of those two is arrested for another crime. Erskine and Colby try to pick up the trail of the doctor. Meanwhile, the physician is playing a desperate game of cat and mouse with the man tracking him.
A crusading newspaper columnist narrowly avoids death in a murder attempt at his home. The van used by his would-be killers was stolen and crosses state lines, bringing the FBI into the case. Erskine and Colby lead the bureau's investigation. But there's more to the case that seems apparent. The columnist utilizes a snitch who's playing both sides. What's more, the person behind the contract on the columnist may be one of his friends.
Erskine goes undercover to infiltrate an Eastern Bloc spy ring operating in the U.S. The inspector has to take on the assignment despite not knowing every detail about the man whose identity he has assumed. The FBI man also will be forced to improvise after a major shakeup has caused the liquidation of the Eastern Bloc official responsible for the spy ring.
A U.S. Marine is stabbed and seriously wounded, causing the FBI to investigate. Erskine and Colby end up on the trail of a gang who steal firearms from a U.S. military facility. The gang intends to sell the weapons to a group of extremists.
Erskine and Colby are assigned to a case involving the theft of valuable jewels. The FBI men will soon need to unravel a web of deceit, involving a father (who a veneer of being a respectable businessman), his daughter and a thief. The father, seeking to protect his reputation, puts his daughter into peril by hiring a hit man to kill the thief. The question is whether the FBI men can crack the case in time.
Jerome Williams, an AWOL U.S. Army private, robs a bank. During his getaway, Williams takes in a young woman hitchhiker. It's only when they approach a roadblock that she realizes Williams is a fugitive. Williams isn't a hardened criminal; he robbed the bank, in part to gain attention. Erskine and Colby lead the FBI manhunt for Williams, who injures two men as the chase continues. On top of everything else, Williams gets the attention of a gang of bikers. Williams has taken jewelry from a businessman worth $20,000.
A robbery of an armored car in Michigan goes badly. But one man, the getaway driver, escapes. The robbers weren't aware of how large a target was involved. The armored car had $500,000. The driver tries to cut a deal with the mastermind of the holdup but is double crossed. The driver, though, manages to escape with all the money. Now, the FBI -- led by Erskine and Colby -- is after the thief along with the criminal who planned the robbery.
A New York-based gambling syndicate has its hooks deep into a mens college basketball team from Jefferson City, Kentucky. One of the team's players is injured when the team doesn't win enough to the syndicate's liking. Erskine and Colby lead the FBI's investigation into a potential point-shaving scandal. Meanwhile, the team now is ready to play for the college championship and the syndicate doesn't want to take any chances. When one player refuses a bribe, the gambling syndicate kidnaps his sister to ensure the final score results in a big payoff.
In Denver, almost $1 million is stolen when three thieves tunnel into a bank vault from an empty building next door that they've rented. Erskine and Colby lead the FBI's investigation. The ringleader, who spent all of an inheritance, plotted the crime so he could win back the woman he loves. The weaknesses of the three conspirators will eventually provide the clues the FBI men need to solve the case.