The Addams household is upended when Gomez and Morticia welcome a new baby boy, Pubert, and Wednesday and Pugsley become determined to get rid of their adored little brother. Meanwhile, the family grows suspicious of Debbie Jellinsky, Pubert’s new nanny, whose interest in Uncle Fester may be less romantic than it seems. As Debbie sets her sights on adding Fester to her list of dead husbands, the Addamses try to save him from her plans.