2 innocent men are iced by a currency exchange bookkeeper, to disguise her embezzlement. The sultry femme fatale's yarn that it was a heist gone bad makes sense at first, because of a wave of such robberies on Chicago's Far East Side. But the murdered customer Halper checks out as a solid working stiff, plus the other stick-ups were solo jobs while this was supposedly a 2 hood hold-up, so M Squad's debonair Lt. Ballinger's sic-ed on the case to soften up hard boiled Ora Kane.

A pair of gun crazy kids are loose in Chicago-- and a young reporter is defending them in the press against Ballinger and "police brutality".

A shady lawyer protects a false heir to a fortune-- by killing the real relative! Ballinger is called in to set everything straight.

Ballinger goes undercover as an immigrant worker to help break an extortion ring targeting foreigners.

Danny Mitchell is trying to find an engagement ring for his girl when he mistaken for a thief by the store owner. A fight convinces him he has killed the old man-- as such Danny's on the run! Ballinger is called in to find the kid before he gets into real trouble.

Val Mooney, hiding out from the cops, sees the perfect opportunity to evade them. When his wife's brother is killed in a massive warehouse fire, he forces her to identify the body as-- VAL MOONEY.

A pair of high-speed motorcycle thugs are robbing gas stations across Chicago. When one attendant gets shot, Ballinger goes undercover as a biker to crack the case.

A famous defense attorney is gunned down in his house. Now Ballinger must piece together the clues to find the kille

Larry Princeton is the master of bank heists-- he plans then sits back while his thugs pull off the job. Except for the last one-- which resulted in a bank teller's murder! Now Ballinger's after him.

Unsuspecting women allow bookmakers to use their telephones in return for payment of $50 per week, but they later learn that their lives will be in danger if they try to get out of the agreement.

Widows have something in common. All their husbands were murdered, and all had life insurance policies with double indemnity. And the widows have the same crooked lawyer. Lt. Frank Ballinger suspects a murder for hire scheme.

The wife of a brain surgeon is abducted and threatened with death if the surgeon goes ahead with an emergency operation to save a critically injured police witness that can implicate a loan shark in two murders.

Young hoodlums use a trade school for criminal purposes.

An innocent man will be executed in 48 hours unless Lieutenant Ballinger can convince a socially prominent woman to recant the false testimony that she gave as a result of a ruthless blackmailer's threats.

Frank must solve several connected homicides wherein convicted muggers are being strangled to death.

Racketeers try to steal profits from a new entertainment establishment run by an old friend of Ballinger.

Lieutenant Ballinger and the FBI have few leads and little time to find a kidnapped socialite with a predilection for visiting jazz clubs. Bound, unattended, and hidden in a condemned building during a cruel Chicago winter, the young woman is in grave danger of dying from injury or exposure before she can be rescued.

Detective Ballinger helps investigate a series of arson crimes that are being used to cover up insurance scams.

Lieutenant Ballinger investigates a possible link between a series of Dark Street purse snatchings and the disappearance of a successful but unhappily married architect.

A former convict and his daughter are being harassed by an old inmate.

A swimsuit model is found dead in Lake Michigan, but physical evidence indicates the she may not have drowned while swimming. Lieutenant Ballinger becomes convinced that she was murdered after he learns that she was a strong swimmer and an iniquitous individual with a large number of unexplained bank deposits.

The M squad is called in after a brutal robbery at the Leslie Fur Salon leaves a man clinging to death. As the investigation progresses, the situation faced by M Squad becomes more and more complex.

A seemingly random dockside shooting leads M Squad on a strange investigation involving fur skins and ancient Inca artifacts.

A D.J threatens to reveal the influence of racketeers in the music industry. Before he can go to air with the information he is gunned down. M squad are brought in to solve the mystery of the death as well as the validity of the information he was going to reveal.

LT. Frank Ballinger takes a personal interest in a case when the wife of convicted murderer Paul Danzig approaches him for help. Danzig has only 20 hours to live and his wife talks openly of stopping the clock. Ballinger has to figure out what she means, and ensure the right man pays for the crime of murder.