Leo is a sea turtle and sea turtles are supposed to swim. He's sure he could if one of his flippers wasn't shorter than the others. He'll try anything to learn, but when none of his crazy fixes get him swimming, he starts to lose hope. Leo meets a starfish with a similar situation and realizes if he concentrates on his three good flippers, instead of his one bad one, he might learn to swim. When a giant ghost crab threatens his cousin Elliott, Leo discovers that caring about others is the only fix he needs.