As Jack and Annie walk to the magic tree house, they worry that this might be their final mission. When they question the magical librarian Morgan Le Fay about this, Morgan doesn't answer their question directly. Instead, she prepares the children to recover the fourth lost story. She shows the siblings a story title written in Greek script and gives Jack a research book about ancient Greece.When they arrive at their destination, they see an olive grove and white tents. Jack researches the scene in the book and learns it is the site of the ancient Olympics. As they near the Olympic grounds, Annie notices that she doesn't see any girls. They finally see a woman on stage at an outdoor theater but realize the actor is actually a man when he pulls a wig off his head. They learn that women in ancient Greece were not allowed to act. They are leaving the theater when they run into a man who is somewhat surprised by Annie's bold act of walkingthrough Olympia. He introduces himself as Plato.When Jack shows Plato the name of the lost story, Plato recognizes the name immediately and ushers Jack and Annie into the courtyard of the author's home. Plato tells them that they must never reveal this poet's identity and leaves to find the poet. As the children read more from their research book, Annie is astounded to learn that Greek girls are not allowed to attend school.Plato returns with a young woman holding a scroll and introduces her as the secret poet. The poet tells Annie that she taught herself how to read and write. Plato explains that the woman will get in trouble if the poem is read in Olympia, so they give the scroll to the children and ask them to take it to their land. As they leave the house, Annie becomes disheartened about Greek society and the things girls are not allowed to do. She tells Jack she is ready to leave.Jack reminds her about the Olympics, which excites her, and she decides to stay. When Plato tells them that Annie cannot attend because she is a girl, Annie thinks the situation is unfair. Jack agrees with Annie and says they will go home, but Annie insists that Jack attend the games while she returns to the play at the outdoor theater. Although he is unsure about leaving Annie alone, Jack goes with Plato to the Olympic grounds.
On the way, Plato shows Jack the gymnasium where the athletes train and takes him into Zeus' temple. Plato tells Jack that the games are played in honor of Zeus, who is the head over all the other gods and goddesses.