Mr. Jenkins, the director at Camp Lone Wolf, has decided to hold a track meet. He's even brought an expert running coach to help the Bailey School kids prepare. The new coach is strangely inspirational -- when she sings, people feel like they can do anything. But when the kids notice the strange resemblance the coach bears to a mermaid, the fact that she refuses to get wet, and that she's planning to run off with Mr. Jenkins, they wonder if this coach is more than she appears to be. Can the kids solve this mystery before they lose Mr. Jenkins and Camp Lone Wolf forever?