Maggie loves attending school, where she and her friends get to play, collect nature treasures, and ride trikes together. Best of all, Maggie looks forward to hearing the class guinea pig, Sweetie Pie's, daily greeting of "Whee, Whee, Whee, Whee, Whee, Whee, Wheat!" But today, Ms. Lamms has sad news for the class: Sweetie Pie has died, and they won't be able to see her anymore. Alongside their grief and worries, Maggie and her classmates devise a plan to show their love for the best guinea pig ever!