This company has gone through allot of changes. They are a bit unorganized as the UK culture is so different from the US culture. The Arlington, VA office was losing people right and left when I interviewed. They were trying to move US operations to New York.
Initial contact was fine, but setting up a time to come in was hard because the people I needed to speak with were never available at the same time. I came in three times. Initially met with potential boss, and the Managing Director. The actual interview was often off topic. Just be prepared to answer some questions like what book are you reading now? What is your favorite book? etc...
Company was too disorganized for me and I knew that the position I was interviewing for would have to take on allot more than they discussed because there were so many holes in the staff.