Administrator Keith F is one of the Admins to the 39 Clues Message Board. He should be dubbed "The Mysterious One" because no one knows anything about him. However, recent info proves that he works on the rest of the 39 Clues site along with Admin Gavin B. He wrote a 200-page document describing how the Extreme Mission One would work.
He was the most active admin on the Infinity Ring site, helping MBers there when there were glitches in the episode. Recently though, he has not been on The Infinity Ring Message Board, presumably because the series is over. He is now one of the most active admins on The Spirit Animals Message Board.
He also joined the IRMB's SQ government as "the call of pie was too strong".