When you live on the shore, every day is a beach day... When best friends Cora and Shelly get home from school, they shimmy into their swimsuits, pick up their buckets, and race to the water. That's when the sandcastle building begins! Together, the girls raise towers, dig moats, and use seashells to make their creations shine. Then one day, Shelly announces that she's moving to the city to live with her mom, and suddenly Cora doesn't feel like building sandcastles anymore. What's the point when they'll just wash away? With gentle prose, creator Ellie Peterson explores the difficult feelings of loss and sadness when a friend moves away, while reminding young readers that-with the right tools and a willingness to try again-who's to say a friendship can't last forever?