Earl in the Desk (Dramatic Irony)
One of the central instances of dramatic irony is Earl's hiding spot in the desk. When Earl arrives, Hildy is thrilled to have cornered her story, but unfortunately, they are confined to the pressroom. If they leave, they might run into another journalist who could steal the Earl Williams scoop. As a temporary solution, Hildy and Walter have Earl climb in a roll top desk to hide until they can transport him safely to Walter's office for some privacy. For much of the film, Earl is waiting quietly inside the desk as a slew of characters run in and out looking for him. The viewers' knowledge that Earl is in the desk aligns them with Walter and Hildy's plight and creates suspense about whether or not they will be found out. The dramatic tension is strongest when the reporter Bensinger comes back, as it is his desk in which Earl is hiding. Walter must make some lofty promises to Bensinger in order to send him away from the office without retrieving something from his desk.
Hildy Loves Being a Reporter (Situational Irony)
One of the ironies of the film is how much Hildy enjoys being a reporter and covering the Earl Williams case, in spite of her early protestations. While she tells Walter that she wants to leave the business and move on once and for all, she cannot help but be continually pulled back into her task. The life of a journalist clearly fulfills and excites Hildy, who wants Walter to believe the opposite. While in the first scene, she disparages the life of a journalist as chaotic, unethical, and unpredictable, we soon see that this is precisely what she loves. Her truest self is a reporter, as she so unceremoniously announces to Bruce—while furiously typing up her story—that she is a "newspaperman," not a "suburban bridge player."
Walter Hits the Desk 3 Times (Situational Irony)
After they hide Earl in the desk, Hildy and Walter must find a good way of transporting him to Walter's office without anyone discovering the escaped convict. Walter tells Earl that if he hits the desk 3 times, that will be a kind of signal. Later, when the sheriff accuses Walter of hiding the criminal and announces that he is going to impound the property, Walter sees an opportunity to get the desk out of the office without anyone finding Earl and encourages the sheriff and his men to remove the desk. When Mrs. Baldwin declares that Walter and Hildy are hiding Earl, however, Walter becomes indignant and absentmindedly hits the desk 3 times. Thinking Walter is giving a signal, Earl taps back. Thus, it is Walter's fault that Earl reveals himself at all at the end, because he mistakenly gives a signal without meaning to. Just in the moment when Earl could have been removed from the office without a hitch, Walter sabotages his own interests by tapping 3 times.
Hildy Sees Walter Encouraging Her Marriage to Bruce as a Rejection (Situational Irony)
Hildy stubbornly maintains that she is eventually going to board a train to Albany with Bruce at the end of the day. While she agrees to take on the Earl Williams story, she does so with the caveat that as soon as she's finished she will leave town and quit journalism forever. Walter has other plans, however, and keeps thwarting her departure in various ways. By the end, when they have gotten their story, he encourages her to go to Bruce for the first time. He tells her that Bruce will give her all the things that he cannot and that he wants her to be happy. Hildy is so used to Walter trying to sabotage her relationship with Bruce that she is confused by his sudden change of heart. When Bruce calls and informs her he's in jail once again (Walter's doing), Hildy erupts in a rare crying fit, and admits to Walter that she interpreted his encouraging her to marry Walter as a rejection of her. It is ironic that throughout the film, Hildy has expressed frustration with Walter's continual sabotage, but at the end, when he doesn't do it, she is worried that he doesn't care.