One day, Polly & her friends are given homework about lunar eclipses. Lila is nervous because if she does not do well on the assignment she will be grounded & unable to play in the band at the school dance. Polly & her friends organize a trip to a water park to learn about lunar eclipses. Meanwhile, Beth, a classmate who is jealous of Polly, decides to sabotage their trip by giving Lila a camera that's been tampered with, so that she will be unable to photograph the eclipse. Polly & her friends have fun at the water park. At night when they start to do their homework they notice that a dolphin calf is stuck near the beach, & they decide to help it return to the sea. When they return home, Lila discovers that the photos she took of the eclipse were spoiled because the film was full of double exposures. But in the end, Polly creates a plan to save the project presentation with the help of drawings made by Ana, and Polly & her band manage to perform at the school dance after all.