I submitted my resume at a career fair, and had a case interview over the phone about two weeks later. After the case interview I was contacted hours later (they said expect word back in 3-4 days, but they seem to be pretty efficient in this regard) to set up my flight for their power day. Power day was pretty challenging. There were 7 other candidates there at the same time. We did two case interviews and one behavioral interview. One case was about the same difficulty as the phone interview, but the other case was advanced. Some people were asked to stay for an additional interview that was not initially scheduled.