Anxious to help her pretty sister Eileen, an aspiring actress, Ruth Sherwood, a reporter for the Columbus, Ohio Courier , writes a glowing review of Eileen's performance before the play in which she is appearing opens. Consequently, on opening night, when Eileen is replaced by another actress and the Courier runs the review, Ruth is fired. Grandma Sherwood, the sisters' sympathetic grandmother, urges Ruth to travel to New York to advance her writing career, and when Eileen insists on accompanying her sister, the girls's father, Walter Sherwood, reluctantly gives them $100 for their journey. Shocked by the high cost of New York rent, the sisters are talked into renting a Greenwich Village basement apartment by the building's landlord, Appopolous. As they hand over the rent, an explosion rocks the building, and Appopolous explains that workmen are blasting nearby to build a subway tunnel. That night, in the sweltering heat, the girls leave their window open and are harassed by a pair of drunks ogling them from the sidewalk above. When Lonigan, the local constable, chases away the drunks and warns the sisters to stop causing disturbances, Eileen bursts into tears. The next day, while seeking employment at the Wallace Theatrical Production office, Eileen meets reporter Chic Clark, who asks for an interview in order to pursue the pretty actress. Meanwhile, Ruth goes to Manhatter magazine in search of a job. There, Robert Baker, the magazine's editor, is criticizing Ralph Craven, the magazine's owner, about his outdated policies. To prove his point, Robert asks Ruth's opinion, and when she echoes his criticisms, Ruth and Craven argue and she runs out of the office, leaving behind her manuscript. Intrigued, Robert finds Ruth's address on the manuscript and decides to pay her a visit. Upon returning home, the discouraged Ruth learns that Eileen has invited drugstore clerk Frank Lippincott to dinner. After a drunken man searching for Effie Shelton, the apartment's former tenant and resident psychic, wanders in, Eileen summons their neighbor, "The Wreck" Loomis, a burly football player, to throw him out. Wreck then asks if he can sleep in their kitchen while his mother-in-law, Mrs. Wade, who is unaware that her daughter Helen is married, comes to visit. Soon after Lippincott arrives for his "intimate" dinner, Chic knocks at the door, looking for Eileen. Next, Wreck joins the party, followed by a man carrying the unconscious Effie, whom he plants on a couch. Robert then comes to the door, declares that he has read Ruth's manuscript and invites her to dinner. Over their meal, the loquacious Robert convinces Ruth to use her talents and write about her eccentric life in New York. Ruth takes his advice, and when she presents her completed story, titled "My Sister Eileen," to Robert, he wants to publish it immediately. When Craven rejects the article, however, Robert announces that he is quitting after the next issue comes out. As Effie, Wreck, Helen and her mother converge at the sisters' apartment, Effie lets slip the fact that Helen and Wreck are married, much to Mrs. Wade's dismay. Soon after, Ruth's spirits are restored when a call comes from Chic's paper, sending her to Brooklyn to cover a story about the docking of the Portuguese Merchant Marine fleet. After Ruth hurries to Brooklyn, Chic appears at the apartment and admits to Eileen that the assignment was a ruse so that he could be alone with her. As Chic makes unwelcome advances to Eileen, Robert arrives, rescues Eileen and invites her and the absent Ruth to dinner that night to celebrate quitting his job. After Robert leaves, Ruth runs into the apartment followed by a pack of Portuguese Merchant Marines. When the sisters form a conga line to lure the sailors outside, Eileen creates a commotion on the street and is jailed for disturbing the peace. The next morning, Grandma and Mr. Sherwood come to visit the sisters, and as Ruth tries to conceal Eileen's predicament, Wreck and Helen interrupt with news that they have gotten married again for the sake of Helen's mother and Helen blurts out that Wreck had been living with the sisters. Next, Eileen, escorted by the Merchant Marines, arrives at the apartment and the commander presents her with a medal for spending the night in jail. Mortified, Mr. Sherwood insists the sisters return home and leaves to buy them railroad tickets. As Ruth packs her suitcases, Robert comes to the door, brandishing her story in the newest issue of the Manhatter , and gives her with a check for $250. After Appopolous appears and declares that the blasting has ended, Ruth signs a six-month lease for the apartment and, when her father returns, announces that she plans to stay in New York. Craven then arrives and offers Ruth a contract for her "Eileen" stories. She consents on the condition that he introduce Eileen to some of his theatrical producer friends. As they all leave the apartment to celebrate, three workmen drill through the floor from the subway tunnel below.