From what I've heard, it's a pretty short conversation (15ish minutes). They'll probably ask "why law," "why Harvard," and, potentially, questions related to your resume or personal statement.
Congratulations on the interview! Out of curiosity, what type of questions did they ask you? If you interviewed with Northwestern as well, was it similar to that?
I received an interview invite and have done no ... and can administer a mock interview? If someone else is also ... planning to interview and want to do a ...