It's been 2 years since Amy first became a mermaid. By now, you think she would be a pro at keeping her secret. WRONG! When Tess and Amy take a day trip to the dog beach, Tess decides to go. Lo and behold, the scrapbook that Kelsey made for Amy floats up. Now, it's up to Amy and the girls to retrieve the scrapbook before Tess can find out.