Muffy's cousin Mort comes for yet another visit and they are having a good time-sharing. But later a fight breaks out between them and they don't want to speak to each other. So Muffy uses a magic spell to get a new friend who suddenly appears, a mouse named Lucille. But it makes Muffy madder when she becomes friend with Mort. Eventually Muffy and Mort fight over Lucille until she disappears and Muffy and Mort finally make up and agree to share from now on.