David seeks his father's help in winning over Felice. Mel and Jackie invite David, Donna and her parents over for dinner. Felice makes snide remarks about the pre-prom incident from four years earlier, the fact that Jackie and Mel are not married, and David's mental problems. A furious Donna refuses to come to her parents' house for Christmas. Felice apologizes to David and asks him to arrange a truce. Kelly's father fails to show for dinner, but a young woman arrives in his place. She stuns Kelly by revealing that she is her half-sister, Joy Taylor. Kelly is angry to learn that her mother hid the truth, and she and Joy become friends as they compare notes about their absentee father. Chancellor Arnold immediately hits it off with Samantha at his Christmas party, making Steve and Clare uncomfortable. The gang picks names from a hat to decide who will exchange gifts. Brandon and Tracy struggle with their gift selections, as neither wants to send the wrong message. While shopping for Kel

Valerie becomes depressed when her mom, Jim and Cindy all fail to come to graduation. She tries to make amends with Kelly after overhearing her push Brandon to evict her. Val pleads with Steve to lobby Brandon on her behalf, but he still kicks her out. She checks into a motel across the street from the bluff where she once contemplated suicide. Brandon finds a suicide note and learns Val's probable location from David. Donna ponders taking her relationship with David to the next level. David helps Steve and Muntz with a senior prank. Kelly is furious when her father insists on attending her graduation. The gang receives invitations to a special grad party with a ""roaring '20s"" theme. Kelly's sister Joy confesses that Bill is responsible for the event.