Shirley and her parents are spending a relaxing day taking a trip to the seaside. While her mother and father settle down in their folding deckchairs to snooze the day away, Shirley has entirely different plans. She steps away from the beach blankets and instantly sets sail for uncharted seas. In her wild imagination, she is embarking on a thrilling pirate adventure, fighting off scoundrels and searching for deeply buried treasure. Back on the sandy beach, her mother is constantly calling out familiar, nagging warnings about avoiding stray dogs, staying away from the sticky tar, and not getting her clothes wet in the cold ocean. Her parents have absolutely no idea that their daughter is currently busy battling a pirate ship just a few steps away. Jump into this funny, clever story that shows exactly what happens when a boring beach day turns into an epic imaginary voyage.