In the garden pavilion of his father's house, Johnny Tarleton is lounging comfortably, when his sister Hypatia's fiance, Bentley Summerhays, arrives with an offensive air of superiority. Threatened with a beating, Bentley throws himself on the floor and screams, bringing Mrs. Tarleton and Hypatia to his help. They lead him away, while Johnny, to relieve his feelings, smashes a punch bowl with full approval of Lord Summerhays, Bentley's father, who has just arrived.
Mrs. Tarleton and Hypatia have a long talk, in which the girl expresses her concerns whether members of the aristocratic Summerhays family are laughing at them behind their backs. She has agreed to marry Bentley because, though he is "a little squit of a thing," he has brains, which the rest of her suitors lack.
Returning with the elder Tarleton, Bentley jokingly calls him his "adopted father." He explains that his college friend, Joey Percival, had three fathers his own, a tame philosopher living in his house, and an Italian priest. This, in Bentley's opinion, has broadened Joey's outlook.
Hypatia is left alone with Lord Summerhays, who on a previous visit had proposed to her, despite their difference in age. She tells him she is sick of her humdrum, lady-like existence; as her father says, she "wants adventure to drop out of the sky."
This is precisely what happens when an airplane makes a forced landing in their garden, smashing the greenhouse glass. Its pilot is the much-fathered Joey Percival. His passenger turns out to be a woman, Lina Szczepanowska, member of a famous Polish family of acrobats. The elder Tarleton, who is a notorious womanizer, tries to seduce her. She spurns him, but they shake hands and she takes him off to the gymnasium for some much needed exercise.
A peculiar young man, brandishing a pistol, enters the pavilion and conceals himself in a portable Turkish bath which is awaiting installation in the mansion. Here he sees Hypatia pursuing Joey with most unlady-like alacrity. Tarleton comes in just in time to catch a glimpse of the two running off when he is held up by the new arrival, who accuses him of having, years ago, seduced and abandoned his mother, Lucinda Titmus. When Tarleton denies all knowledge, the man prepares to shoot him, but Lina enters and neatly disarms him.
Joey and Hypatia run in, and Joey catches her just inside the pavilion. Joey is about to throw "Gunner" out, when Mrs. Tarleton recognizes the photograph of Lucy Titmus, whom she had befriended long ago. She immediately takes the stranger under her wing.
Hypatia, obviously taken by Joey, denies her engagement to Bentley, which sends him off in another screaming fit; but Lina picks him up and carries him off to the gymnasium, while Mrs. Tarleton takes Gunner for a meal and a rest. Asked about his "intentions," Percival admits that he cannot afford to marry Hypatia; he must first have a settlement of 1500 pounds a year. Hypatia asks her father to "buy the brute" for her, and Tarleton eventually submits.
Lina comes back and insists on getting the airplane repaired, as she cannot bear the stuffy house, where people think of nothing but love-making. Already she has had proposals from Tarleton, Lord Summerhays, Bentley, and finally Johnny Tarleton. Since Joey refuses to fly again that evening, Lina decides to handle the airplane herself, taking the terrified Bentley who is now in love with her as her passenger. At the entreaty of Lord Summerhays, however, she puts off the flight until the next day. The play ends with Hypatia exclaiming her great relief that there is nothing more to be said.