The firm really likes to put pressure on everything you say! If you mention an article, or something which is going on in the world, make sure you are knowledgeable enough on the topic to have a full-blown debate.
Also, prep some unique questions for the end. Most people tend to ask about the international strategy, try to have a range of questions prepared and choose one which will best match your interviewers. E.g., if you're with a competition partner, try ask them about something relating to that practice area.
The article part of the interview, make sure you defend your point strongly!! They tend to play devil's advocate and try to make you doubt yourself, but just stay firm and you'll be fine!
Good luck