Barney asks Ted to keep dating Carly, a much younger woman, even though she and Ted have nothing in common.
Tim refuses to take off a Cinderella dress during March Madness; Matt gets unsolicited advice for the prom; Jen sets Matt up on a blind date.
Joy's younger sister, Jill, comes to visit; Melanie helps Victoria write a children's book; Elka and Mamie Sue welcome British royalty to Cleveland.