An old friend asks Mike to reason with a young man who refuses to identify the murderers of a drugstore owner in his old neighborhood. Mike is no more successful than his sister or the police in persuading the youth to talk, but when the witness is found murdered the next day, Mike decides to bring in the killers on his own.

A psychiatrist fears that his patients are being blackmailed. He hires Mike to find out if his fears are founded, how the privileged information is being leaked and who is preying on his clients.

Showgirl Ruby Duvall is roughed up by her future sister-in-law, arrogant society snob Joyce Conroy, and offered $5000 not to marry Philip and soil the family name. It seems an open-and-shut when Ruby is found dead in her dressing room after a visit from Joyce. It's all too obvious for Mike after learning of another backstage visitor that night: Ruby's violent ex-con ex-boyfriend who refused to let Ruby go.

A friend from the old neighborhood asks Mike to travel to Chicago to claim the body of her son. While visiting the Windy City, Mike learns that the young man was murdered and the police don't appear to be interested in investigating the crime. When Mike visits the murdered man's room to pick up his personal effects, he is attacked and brutally beaten by a pair of thugs who want to know where "it" is. Mike has no idea, but he's determined to find out and make the two goons who attacked him which they'd never been born.

Mike receives an anonymous letter with a $300 retainer hiring him to investigate the disappearance of a parking lot attendant. Mike learns that the man was defrauding the owner by marking wrong arrival times on parking tickets and pocketing the proceeds. When the man was found murdered, he traces the killer back to the company's headquarters.

Mike is hired to dissuade a pretty blonde from blackmailing his client with a tape recording of his extra-marital indiscretions. Mike finds the woman hanging from the ceiling in her apartment and, after his client is arrested for murder, investigates other parties who had reason to want the young woman dead.

A homeless man tells Mike that he's the victim of a double cross and a nice old man confesses to a murder.

Am ex-con he'd help send to prison makes a death threat against Mike. Believing its just a sick joke, Hammer decides to meet with the man.

Mike's slippery friend Al Sparks skips town because of a gambling debt. He turns up in Forge River charged with murdering the female owner of the diner where he worked. Hammer discovers everyone fears Todd Stryker, the man who runs his wife's huge lumber company and wields all the power in town. Stryker's relationship with the dead woman is a secret he wants to keep.

Mike investigates a $50,000 jewelry heist and double-murder for the insurance company. He gets a tip that the thief and murderer is hiding in a nearby hotel and kills the crook in a gunfight. When Mike learns that the dead man was a known jewel thief who never carried a gun, he suspects that he was tricked into shooting a man by his double-crossing partner and sets out to bring the other gunsel to justice.

Hammer is hired by a gypsy to clear her boyfriend Carl as an accomplice in robbery. Carl's brother Van is a monkey grinder and after Hammer questions him is murdered. The monkey (Banjo) saves Hammer's life as he solves the crime and clears Carl.

After getting in debt to a couple running an upscale dice game, Paul Redmond is roughed up by their collections thug Murphy before disappearing. Murphy's a renegade private eye who lost his license and is now muscling in on the gambling racket. The wife of the missing Redmond hires Mike to find her husband.

A dying man comes to New York and hires Mike to find the attractive young woman he remembers from 15 years earlier. Mike tracks down Sally Bryant to the fleabag Central Hotel and discovers she's hardly beauty the old man remembers. She's slovenly, hard-edged, and married to a greedy husband with a stripper girlfriend.

Mike investigates a dishevelled man's wild tale about a man that he killed six months ago dying a second time in a car accident two days ago. When his client turns up dead, Mike follows his only clue, the phone number of a pretty piano player billed as "Miss Patti".

While waiting for his car to be repaired at a friend's combination garage/used car lot, Mike gets involved with three unsavoury characters who are very interested in a Jaguar sports car that has bullet holes in the back of the driver's seat with blood stains to match.

Mike discovers his girlfriend's roommate has been murdered and launches his own investigation. He discovers that she was killed for a diamond she was trying to fence and tracks the murderer to the Brussels World Fair.

A death row convict confesses to a murder that another man was executed for three years earlier and threatens to supply proof after his execution.

Mike is hired by an ex-con who now runs an amusement park in New Jersey. The former con-artist has received blackmail notes demanding $25,000 or else he reveal that the old man lied about his identity on his business license applications.

Mike investigates a murder and confidence game involving a New York theater group.

A blackmailing showgirl is found murdered and one of Hammer's friends is the number one suspect.

Mike's vacation at the 1958 World's Fair in Brussels is interrupted by a case. Wealthy Wilma Puttnam asks Hammer to investigate the people claiming to have the daughter of her late sister who died in the Nazi concentration camps. Mrs. Puttnam wants to be sure it's really Anna/Derna before paying the $5000 they're asking for.

Tom O'Rough is severely beaten en route to Mike's office. He's concern that Si Loomis, a small-time crook, has won the heart of his employer, Edie Sanford, and she's about to lose her money and her company to the grifter. When Mike can't force the crook to back off and can't convince the Edie that she's fallen for a criminal, he tries to use Loomis' pretty young secretary to get enough evidence to break up the romance.

Mike returns to his old neighborhood when gunsels working for a protection racket murder a boyhood friend. Before long, his investigation into the gang's criminal activities results in more fatalities.

Mike is hired to find the murderer of a newspaper reporter. The trail leads to a ballroom whose hostesses, usually small-town girls with no relatives, frequently disappear.

The lawyer for a wealthy couple asks Mike to help their niece kick her heroine habit. Mike works on two fronts: helping the young woman withdraw from the drug and finding the pushers that got her hooked in the first place.