Construction contractor Jiggs and his overbearing, social-climbing wife Maggie are visited in their posh Park Avenue, New York apartment by the snobbish Mrs. Kermishaw, who, unaware that Jiggs is Maggie's husband, tells her that Jiggs is a "hybrid" and that she wants him removed from the building. Jiggs makes his presence known during Mrs. Kermishaw's visit and embarrasses Maggie, who then punches her husband for ruining her chances to get into the society Blue Book . When Jiggs stumbles down the stairs of his building and into a parked car, he happens upon his daughter Nora, who introduces him to her date, Junior Kermishaw, son of F. Newson Kermishaw, a dishonest developer who is planning to tear down Dinty Moore's Tenth Avenue saloon. Dinty's nephew Danny, an architect, is in the employ of Kermishaw but is unaware that he plans to welch on his promise to Dinty that he will modernize the building and let the saloon stand. Kermishaw's neighborhood improvement plan is nothing more than a front that he plans to use to take over the neighborhood. As part of his scheme, Kermishaw begins circulating a petition containing a clause in small print that turns over ownership of Dinty's saloon to him. The petition is soon signed by Maggie and all the patrons of Dinty's saloon. Meanwhile, Junior proposes to Nora and asks Jiggs for his blessing to marry his daughter, even though Danny is in love with Nora. When two men present Dinty with an injunction ordering the closure of his saloon, Dinty realizes that he made a terrible mistake in ignoring the small print of the petition, which also stipulates that its patrons refrain from drinking at any establishment. Jiggs is blamed for the fiasco by Dinty and all of the saloon's patrons, and is banished from the bar. Distraught, Jiggs wanders the streets and happens upon Danny, who is also upset because he knows that he has been had by the Kermishaws. Danny decides to fight back, though, and begins circulating a "counter petition" and goes to the Kermishaw Holding Company to slug Junior. Danny succeeds in reopening Dinty's saloon, and he is reunited with Nora. Later, an attempt by Kermishaw's thugs to "rough up" the patrons of the saloon is called off when the leader of the thugs recognizes Murphy, a regular habitué of the saloon, as an old friend.