On her seventeenth birthday, Carrie (AnnaSophia Robb) is torn between an opportunity to mingle with New York’s literati and spending time with her friends and Sebastian (Austin Butler). Mouse (Ellen Wong) goes to extensive lengths to impress a Harvard alum who has her eyes set on West (guest star RJ Brown), with hilarious results. Walt (Brendan Dooling) starts taking responsibility for his previous actions. Elsewhere, Dorrit's (Stefania Owen) search for the perfect gift for Carrie lands her in a sticky situation with romantic possibilities.