Phoebe and Susan Throssel are sisters living in Quality Street. Phoebe is courted by Dr. Valentine Brown and her sister and noisy neighbors expect a proposal shortly. When he instead enlists in the British army during the Napoleonic Wars claiming he has no 'sweetheart', the two sisters are crushed. Ten years later, Valentine returns to find the sisters are teachers of their own school, 'Misses Throssel School for Boys and Girls', and are now both, "old maids". Valentine asks Phoebe to the homecoming ball, but he is very "put out" at realizing how worn-out Phoebe looks. On a whim Phoebe puts on a ball gown and does her hair as if to prove that she is not that much different from 10 years earlier. When Valentine comes to try to persuade her to go to the ball, he doesn't recognize her. She decides to play on his confusion, telling him Phoebe doesn't feel well, and introduces herself as "Livvy", Phoebe and Susan's niece. Dr. brown and Livvy go to the ball together. At the ball, Phoebe continues her game and attracts many male admirers, plus attracts the suspicions of three very snoopy spinster sisters. Everyone is persuaded that Dr. Brown is in love with Livvy, but just when Phoebe think she will propose he scolds her for being a flirt. He tells her that is Phoebe whom he loves and not her. Phoebe desperately wants to return his affection, but can't for three noisy spinsters are keeping her under control suspecting she is the one impersonating Livvy...