Very stoic and unflappable BBC Newsnight anchor Kirsty Wark surprised viewers when she signed off news last night. 

Wark, who shot to prominence across the pond in the 1980s with her one to one interview with Margaret Thatcher, showed she does have a sense of humor. 

She hinted via Twitter that something special was planned.

So just what did the anchor do?

Let's roll the video: