When The Critter Club takes in an abandoned pig named Plum, the girls are really excited. They’ve never had a pig at the club before! They love learning how to take care of Plum. And they especially love watching Ms. Sullivan’s dog, Rufus, interact with the pig. But no one is happier about the club’s guest than Ellie.

Soon after Plum arrives, Ellie starts having some unusually good luck. She does really well on a test for her least favorite subject; she aces an audition for a play at a local theater; and she wins a prize at school! Ellie is sure that Plum is bringing her good luck. So when the rest of the girls tell Ellie that they’ve found someone to adopt the pig, Ellie knows she should be excited...but she’s not. Will Ellie’s good luck turn bad once Plum leaves?