Rita and Mirabelle are collecting and labelling shells on the beach. Rita finds a shell with a hermit crab inside, and wants to keep it, but Mirabelle needs it for the collection. They fight over it, and Mirabelle eventually gets it from Rita. But when she finally sees hermit crab, she realises that she can’t keep it. She puts it back into the sea, along with all the other shells she has collected.