The fourth grade is studying fish, and that means a trip to the Cherrydale Aquarium! Everything is going along just swimmingly until Ms. Sweet drops her brand-new engagement ring into the tankâand Katie turns into a fish! Now sheâs stuck in a tank and sheâs all wet. Well, at least she can try to find Ms. Sweetâs ring . . . although that may be difficult when Katie the clown fish is being chased by a shark!