Third job interview for same position?

I have interviewed on 2 separate occasions for this position. It is vacant again ( 2 months after it was filled, and I was thisclose to getting it!) I am going thru the interview process for a 3rd time. What can I possibly say to get the job this time? I'm wracking my brain, and don't want my frustration to bleed through. I really REALLY want this job. Help!