Penelope gets lost in the woods during a storm and finds her way to a castle where the Queen lives. The Queen lets Penelope stay the night but puts a pea under her mattress as a test to see if Penelope is truly a princess. Penelope tosses and turns all night from the discomfort of the pea. In the morning, the Queen and Prince are surprised that Penelope had such an unpleasant night, proving she must be a princess. They get married in the end. The story has a clear beginning, middle, and end to keep it simple for children to follow along.