Carrie is thrilled when the junior-senior lock-in provides the perfect cover for a night out in Manhattan with Larissa and her Interview co-workers - until a surprising encounter turns her night upside down. Maggie and Mouse confront Sebastian about his feelings for Carrie and tell him he better make a grand gesture if he stands any chance of winning her back. Harlan finally convinces Tom to go on a double date, with surprising results. Meanwhile, Maggie tries to find the courage to tell Walt about Simon before Donna LaDonna does.