A charming story invites young readers to reach for treasures left by a mermaid, including removable letters and four surprising novelties. On her first day of vacation, Holly finds a mermaid's purse on the beach. She wants to give it back, but has a few questions for the mermaid first. Imagine how thrilled Holly is the next day to find the purse again, with a letter inside - and a request to help find a mysterious gold key!