Prunella gets jealous when Marina joins yoga lessons with her and her mother, and Marina ends up doing better poses than Prunella. This causes Prunella to think that Marina is "stealing" her mother from her, but her mother assures her that she will never like Marina as much as her daughter. Arthur joins an inter-scholastic checkers tournament, facing off against Brain. However, Arthur's friends take the game too seriously, and he is frustrated with their unwanted support.