Arnold ignores warnings and continues to drop water balloons from the balcony. Mr. Drummond's decision to punish Arnold for the prank with a spanking becomes a learning lesson for Willis too, when he insists that he be the one to spank Arnold -- but where's Arnold?

LaWanda Page guest stars as a cousin of Willis and Arnold who, after seeing the boys in their comfortable new surroundings, knows she should stay closer to her long-lost little relatives.

Leaving Willis in charge of the house for Kimberly's slumber party is a mistake Mr. Drummond soon regrets as the ensuing chaos disrupts his own date with a lovely lady. The Facts of Life stars Mindy Cohn, Kim Fields, Julie Anne Haddock, and Molly Ringwald guest star.

Dudley, fearing his foster father's lost job means he's headed back to the orphanage, cons Arnold into getting Drummond to consider adopting him into their family.