A young dance student accidentally cripples a teacher she doesn't like.

Meg Merlin, a young ballerina studying at the Ballet School of the Metropolitan Opera Company in New York, would rather spend hours at a time watching the dance movements of her idol, Ariane Bouchet, than attend her classes. Meg's lack of enthusiasm for her classes nearly results in her dismissal from the school by her teacher until the kindly Mr. Paneros, a friend of Meg's aunt, intervenes. One day, during rehearsals, Meg learns that the school has hired the famous ballerina Lady Anna La Darina, known by many as "The First Lady of Ballet." Mistakenly believing that La Darina has arrived to replace Ariane, Meg undertakes to humiliate the new dancer and sabotage her attempt to settle into the school. She begins her campaign by turning off the lights when a photographer tries to take Ariane and La Darina's photograph. Later, when Phyllis Brigham, another young dancer, tells Meg that she prefers La Darina to Ariane, Meg strikes her. Meg is severely reprimanded for her assault on Phyllis, but she continues her campaign against La Darina nevertheless. During a performance of "Swan Lake," Meg, intending to pull the light switch on La Darina's solo sequence, accidentally hits the trap door switch instead, and sends the dancer falling through the stage. A physician later determines that the damage to La Darina's spine as a result of the fall is so extensive that she will likely never dance again. Though Meg has decided to keep her misdeed a secret, Phyllis and her friend, Josie Devore, suspect that Meg is the culprit and blackmail her. Time passes, and Ariane, who is revealed to be selfish and devoted more to clothes and fame than ballet, proves herself a poor idol for Meg. After Ariane decides to leave the company to marry, La Darina eventually returns to the school as a ballet supervisor and takes a special interest in Meg's promising talents. As Meg and the kind La Darina strike a friendship, Meg makes a number of unsuccessful attempts to confess her responsibility for La Darina's crippling fall. One day, Josie, jealous of the attention that Meg is gettting from La Darina, reveals Meg's secret. When Meg learns that she has been exposed, she runs out of the school seeking a quiet place to hide in shame. Mr. Paneros eventually finds Meg, and she tearfully confides in him. After Mr. Paneros tells La Darina about Meg's confession, La Darina forgives her.