The story is about a young girl named Rosaura, who has been invited to the party of a wealthy friend. Her mother does not want her to go because she will not fit in at a rich person’s party, but Rosaura tells her mother that “rich people go to Heaven too.” Her mother works for the girl's family and thinks Rosaura will just be seen as the maid’s daughter.
Rosaura is excited because there will be a magician with a monkey at the party. Her mother scoffs at the idea, not believing her. But she starches Rosaura’s Christmas dress and helps her do her hair with apple cider to make it shiny. When she gets to the party, Rosaura asks about the monkey and sees it in her cage. Then she is asked to bring a jug of juice into the party.
Rosaura is accosted by a girl with a bow who demands to know who she is. Rosaura says she is Luciana’s friend, but the girl tells her she is Luciana’s cousin and she knows all of her friends. Rosaura answers, as her mother told her to, that she is the daughter of the employee. The girl with the bow responds with derisive confusion, and then the housekeeper, Señora Ines, interrupts and asks Rosaura to serve hot dogs.
Rosaura enjoys the party, winning at the games. Rosaura loves passing out the cake slices, and she gives the girl with the bow the smallest one. Rosaura even assists the magician.
At the end of the party, Rosaura does not get a party favor like the other children. She gets paid.
Sefiora Ines didn't look in the pink bag. Nor did she look in the blue bag. Instead she rummaged in her purse. In her hand appeared two bills.
"You really and truly earned this," she said handing them over. "Thank you for all your help, my pet."
Rosaura is horrified to learn that she wasn’t at the party as a guest—she was the hired help. Through this encounter, she finally begins to understand social class.