The gang attends a Halloween costume party at an old brownstone mansion with Steve playing Zorro, Donna dressed as a mermaid in which the costume limits her mobility, and Brenda and Dylan going as Bonnie and Clyde. But the party is highlighted by Kelly's very revealing bewitching costume, but low-lighted when one student makes an unwanted advance on her. Meanwhile, David skips out on the party to meet with Scott where they reminisce about the "good old days" while waiting for an egg fight with some neighborhood kids that never materializes. Also, Brandon and Emily take her twin niece and nephew out trick-or-treating where a real scare begins when they lose the twins.