I arrived at 5.52pm. Lots of people were milling around staring at the clock next to the departures board. I found myself an out of the way spot by the wall to watch the event unfold.
At 5.58 I looked up from my newspaper to find the concourse packed and the surrounding balcony crammed with people here to witness the spectacle.
At 5.59 and 55 seconds the count down began.
At 6pm the assembled crowd paused for a heartbeat then sang "Never gonna give you up..."
The Rick Astley flash mob had begun. There were a hard core group of flash mobbers with print outs of the lyrics. Surrounding them were a bunch of student types making a valiant effort to sing along despite not really knowing the words. Surrounding them were gawpers, pissed off commuters and baffled tourists.
Camera phones were waved in the air, some bloke from a radio station waved a microphone in peoples faces and confused foreigners kept asking me what was going on.
They were confused by my answers and wandered away into the milling crowd. The singing ended and people milled around, not really knowing what to do now that the anticlimactic event was over.