Inspector Cramer takes the unprecedented step of approaching Nero Wolfe for his help on a stalled murder investigation. Leonard Dykes, a clerk for a law partnership, was found dead in the East River. The police found in Dykes’ apartment a list of men’s names and Cramer wishes to have Wolfe’s opinion on it. But other than suggesting Dykes may have been trying to invent an alias, Wolfe can’t help.

A month later Wolfe, is approached by the father of Joan Wellman, a reader for a fiction publisher, who was killed in a hit-and-run incident, late at night in Van Cortlandt Park. After reading a recent letter that Joan had written to her parents, Wolfe realises that the name ‘Baird Archer’, an author whose novel Joan was reading for her employer, had also appeared on the list found in Leonard Dykes’ apartment.

Wolfe orders Archie Goodwin to explore the link between Archer’s novel and the two murder victims. To that end, Archie arrives at the office of Rachel Abrams, a stenographer, mere minutes after she has been thrown out of a window to her death. In the moments before the police arrive Archie confirms that Baird Archer was one of her clients. Wolfe decides to begin the investigation with Dykes, and Archie arranges a meeting with the female employees of Corrigan, Phelps, Kustin and Briggs, the law partnership Dykes worked for. During the meeting, tempers flare and in a resulting argument the former senior partner of the firm, Conroy O’Malley, is mentioned. O’Malley was disbarred for bribing a jury foreman to fix a case, and while Dykes was blamed for exposing him to the Bar Association it becomes clear that all four of the partners have motives to betray him.

Soon after, the four lawyers—James Corrigan, Emmet Phelps, Louis Kustin and Frederick Briggs—approach Wolfe, keen to avoid further scandal. The men agree to send Wolfe all correspondence relating to Dykes, including a resignation letter he submitted. When they receive the letter, Wolfe and Archie discover an odd notation, apparently in Corrigan’s handwriting, which corresponds a verse in the Book of Psalms. The same verse – “Put not your trust in princes, nor in the son of man, in whom there is no help” – was used for the title of Baird Archer’s novel, which confirms to Wolfe that Archer was a pen name of Dykes and his novel a Roman à clef based on O’Malley’s downfall.

Archie is dispatched to Los Angeles to persuade Dykes’s sister Peggy to help them trap her brother’s murderer. Archie writes a letter to the law firm purportedly from Peggy asking for advice over the legal rights of her brother’s novel, and hires a local private detective to pose as a literary agent. Soon after, James Corrigan unsuccessfully tries to acquire the manuscript, resorting to violence and attempted theft in order to do so. Archie begins to tail Corrigan, but soon after his return to New York Wolfe receives a rambling phone call, apparently from James Corrigan, which is abruptly ended with the sound of a gunshot. The police discover that Corrigan has apparently committed suicide, and the next day Wolfe receives a suicide note written by Corrigan confessing to having exposed O’Malley and committed all three murders to keep his secret.

Although the authorities are willing to rule Corrigan the murderer and his death a suicide, Wolfe has a breakthrough and summons the major witnesses to his office. There, he reveals that the supposed suicide note was flawed in one crucial respect; it claimed that Corrigan was aware of the contents of Dykes’ novel, when in fact Corrigan’s actions in Los Angeles clearly demonstrated that he had never seen the manuscript before. In fact, Corrigan was murdered by Conroy O’Malley, who had staged his death as a suicide. O’Malley had discovered that Corrigan had betrayed him via Dykes’s manuscript and had committed the other murders both to frame Corrigan and cover up his actions. After holes in his alibi are discovered, O’Malley is charged and convicted of murder.

Cyril Orchard, the publisher of the weekly horse racing sheet Track Almanac, is poisoned with cyanide during a live soft drink commercial on a popular radio talk show. A media sensation, the case attracts the attention of Nero Wolfe, who is facing a crippling income tax bill, and Archie Goodwin is dispatched to convince the producers and sponsors to hire Wolfe to investigate the crime. The police have identified several suspects, including the show’s host Madeline Fraser; her business manager, friend and former sister-in-law Deborah Koppel; her on-air side-kick Bill Meadows; Tully Strong and Nathan Straub, representatives of the show’s sponsors; script-writer Elinor Vance; Nancylee Shepherd, the head of Fraser’s fan-club; and F.O. Savarese, an assistant professor of mathematics and the show’s other guest.

Although his initial investigations seem unpromising, Wolfe eventually learns that a separate bottle of the beverage being advertised was provided for Fraser, identified with tape around the neck. When pressed, the producers admit that Fraser is unable to drink the beverage she was advertising because it gives her indigestion, and instead drinks iced coffee from the bottle instead. As the marked bottle was the one containing the poison, this suggests that Fraser was the intended victim instead of Orchard.

Wolfe passes this information on to Inspector Cramer, seeing this as an opportunity to claim his fee without further work. When the press — prompted by Archie — criticises him for his lack of effort, however, he is stung into further action but, to Archie’s surprise, begins investigating a different murder. Beula Poole, the publisher of an independent political and economics journal, has been shot dead in her offices days before. Although there is no apparent connection between the crimes, Wolfe is skeptical that two independent publishers would be murdered within weeks of each other without any link. His investigations reveal that the magazines were in fact the front for a sophisticated blackmail operation which targeted its victims using the threat of slander to compel them to purchase subscriptions for a year. This, in turn, brings Wolfe into contact with Arnold Zeck, the shadowy and powerful criminal mastermind behind the operation, who warns Wolfe not to interfere in his affairs.

After the blackmail story is published Walter Anderson, the president of the soft drink company, tries to end Wolfe’s investigations by paying him off and announcing that his company is withdrawing sponsorship from Fraser’s show. With no further leads, Wolfe sends Archie to Fraser and her entourage with a fake letter implicating Elinor Vance in order to try and shake a response out of the suspects. During the meeting, Deborah Koppel dies after eating a piece of candy laced with cyanide. Discovering the letter on Archie, the police threaten to charge him with obstructing justice, but they are interrupted by a phone call from a rival radio station. Wolfe has announced that he knows the identity of the murderer and threatens to reveal it on-air that night.

To avoid humiliation, the charges against Archie are dismissed and Wolfe is permitted to reveal the identity of the murderer in his office. Once the suspects have arrived, Wolfe presses Anderson to reveal the reason he tried to terminate his contract with Wolfe and Fraser’s show. Anderson had discovered that Madeline Fraser had received blackmail letters, and it is revealed that Fraser was being accused of murdering her husband years before. However, while the blackmail syndicate had previously created false claims about their victims to slander them, in this case they had unwittingly stumbled upon the truth – Fraser had in fact murdered her husband. Fraser murdered Orchard and Poole to conceal her secret, and Koppel when she began to suspect the truth. Fraser is arrested and charged with murder. The novel ends with Wolfe receiving a phone call from Zeck, congratulating him on solving the case — and warning him not to interfere in the crime lord’s affairs.

Cheney Boone, the Director of the Bureau of Price Regulation (BPR)[3] is beaten to death with a monkey wrench shortly before a speech he is to deliver at a gathering of the National Industrial Association (NIA), a prominent conglomeration of big business interests. Considerable antagonism exists between the two parties,[4] and the public begins to hold the NIA responsible for Boone’s murder. This attracts the attention of Nero Wolfe, who is facing financial ruin, and with the help of Archie Goodwin he launches a scheme to manipulate the NIA into hiring his services to find the killer.

Wolfe arranges a meeting between the principal witnesses to the case—Boone’s widow and niece, acting BPR director Solomon Dexter and researcher Alger Kates, the NIA executive committee, and select members of law-enforcement including Inspector Cramer and Sgt. Purley Stebbins. The meeting soon degenerates into chaos and bickering, but Wolfe is intrigued by the absence of Phoebe Gunther, Boone’s private secretary and the last person to see him alive, and orders Archie to bring her to him for questioning. Archie finds Phoebe at an apartment owned and occupied by Alger Kates and, after a flirtatious battle of wits, persuades her to meet Wolfe. Phoebe claims that she was given a leather case full of confidential dictation cylinders shortly before Boone’s death, but has misplaced them.

The next day, Wolfe receives a telegram informing him that surveillance of Don O’Neill, the chairman of the NIA’s dinner committee, will have to be suspended—surveillance that neither he nor Archie ordered. Archie therefore follows O’Neill to Grand Central Station, where O’Neill retrieves the leather case from the parcel room, and intercepts him. Faced with the choice of going to the police or to Wolfe, O’Neill is forced to surrender the case, which contains ten dictation cylinders. It becomes clear when listening to them that none of them are the real confidential cylinders, however. When Wolfe calls another meeting of the principal witnesses, Phoebe once again fails to appear—but this time, her body is discovered by the front step of Wolfe’s home, brutally bludgeoned with a length of rusty pipe.

It is clear that Phoebe’s murderer is one of the principal witnesses, and that this person is likely to have also murdered Boone. After nine of the ten cylinders are discovered in Phoebe’s apartment, both Wolfe and Inspector Cramer become convinced that the missing cylinder is key to the murder, but political pressure forces Cramer’s superiors to replace him with Inspector Ash. Ash issues a warrant for Wolfe and Archie and tries to bully information out of Wolfe, leading to a violent confrontation in the police commissioner’s office. Although Wolfe stubbornly refuses to assist Ash, once the warrants are vacated he reveals why the cylinder is so important—on it, Boone identifies his own murderer. Phoebe, a passionate BPR supporter, intended to reveal it once the NIA had been damaged as much as possible by the controversy over Boone’s death, but managed to alert the murderer that she was aware of his identity and was killed for her silence.

After a meeting with Boone’s widow, where she confirms that Phoebe did indeed possess the cylinders, Wolfe takes the unprecedented step of terminating his contract with the NIA and returning the group’s $30,000 fee. As this removes the protection he has received through the status of his clients and will begin a barrage of police and media interest in him, he fakes a mental breakdown in order to hold the police off and buy time until the cylinder is found. Before the police can expose his deception, Wolfe realises that the only place Phoebe could have hidden the cylinder and known it was safe was Wolfe’s own office. He thus has Archie, Fritz and Theodore search the room for the cylinder, where it is found concealed in a bookcase. When played, both Wolfe and Cramer are vindicated; the murderer is revealed to be Alger Kates, who was bribed by Don O’Neill to pass on confidential BPR information and was exposed on the cylinder as a traitor. Having heard the cylinder, Phoebe discovered his guilt but revealed her knowledge to Kates when after pressuring him to return numerous items, possessing sentimental value to Boone’s widow, that were stolen from the corpse to fake a theft.

The novel ends with Archie confronting Wolfe, having realized that Wolfe staged the cylinder’s discovery and in fact knew it was in his office the whole time. He is simply unsure of whether Wolfe waited so long for “art’s sake,” or simply to ensure that he could collect a $100,000 reward offered by the NIA instead of the $30,000 fee. Wolfe does not disagree with either hypothesis, but suggests another motivation: having come to respect Phoebe Gunther’s intelligence and determination, Wolfe decided to continue as far as possible her objective of causing damage to the NIA. In gratitude for saving his career, Inspector Cramer timidly gives Wolfe an orchid for a gift.