A. B. Allen, assistant to paint company president T. M. Bancroft, is the actual brains of the organization. The board of directors, aware of A. B.'s importance to the firm, and worried that she might someday marry, bully the only bachelor among them, Doc "Tut" Tutweiler, to propose. A. B., who has overheard their plans, gives Doc an emphatic "no" to his proposal, but secretly yearns for the kind of happiness her newly engaged secretary has. A. B. buys an option on a deposit of "emeraldite," a previously imported mineral recently found in Connecticut, and easily convinces T. M. and the board that they should secretly corner the market on it. T. M. just as easily accepts the news that she has wired the Omaha office to fire his grandson Jimmie, who he feels will never be a success. When Bancroft comes down with one of his periodic bouts of gout, A. B. and the rest of the board take up residency in his Stamford, Connecticut estate. On the same day, Jimmie visits the estate, not knowing what A. B. looks like because he was fired by telegram. Grandma tries to convince T. M. to hire Jimmie back, but he agrees only on condition that A. B. approves. When A. B. overhears Jimmie saying that he would never beg for his job from a flat-chested, dried prune, she is very hurt and begins to wonder what she can do to make herself more attractive. The kind-hearted Grandma decides to take A. B. under her wing and teaches her how to dress, fix her hair and flirt. A. B., who is used to dealing with men as another man, is incredulous that some would be impressed with women who bat their eyelashes and say things like "you're wonderful" and "do go on." Grandma assures her that what men really like is "a clinging vine," and A. B. determines to give her advice a try. At a houseparty on the estate, the now transformed A. B. is introduced to several men, including B. Harvey Doolittle, but she is only attracted to Jimmie, who still does not know her real identity. Jimmie is equally attracted to A. B., and thinks the ultra feminine woman before him is the opposite of the mannish A. B. The day after they meet, Jimmie has fallen in love with her and takes her to the farm he has been trying to sell for years. While there, Jimmie shows her his invention, an enormous egg beater, and says that if his grandfather buys it, he can ask the sweetest girl in the world to marry him. Soon Jimmie has the egg beater sent to his grandparents' estate. Unknown to him, the rest of the houseparty think the invention is ridiculous and that A. B. has lost her good sense. When Jimmie demonstrates the machine, Doolittle sabotages it, creating a mess that convinces T. M. that the invention is terrible and should be banished from the house. A. B. then secretly asks Tut to give her twenty-five thousand dollars so that she can invest in the egg beater. He agrees, and as part of her plan gives the money to Jimmie, saying that he wants to buy his invention. A short time later, a report is printed in the newspaper that a mystery buyer is purchasing all of the emeraldite properties. Reading this, Doolittle hatches a plan to swindle some of the other guests by saying the he is the mysterious capitalist mentioned in the newspaper. He even talks Jimmie into investing his twenty-five thousand dollars, but A. B. turns the tables on Doolittle by convincing him that Jimmie's farm is rich in emeraldite deposits. Then, with Tut's help, A. B. tricks Doolittle into paying fifty thousand dollars for the farm. A worried Tut then summons T. M., saying that A. B. has lost her head. T. M. immediately rushes to A. B. to see what is wrong and Jimmie learns her true identity. Just then, deliverymen bring back Jimmie's invention and A. B. says that it will be the greatest emeraldite mixer in the world. Once again, T. M. bows to her wisdom. When she and Jimmie are alone, Jimmie says she's wonderful and she bats her eyelashes and says "Oh, do go on!"