Have you ever seen a ghost?

I have, or at least I think Ihave.

It was about ten years ago, Iwas training for my secret job at University and I was lodging in a house inCambridge.  It was a Sunday evening inNovember and I had the house to myself which was a relief as my landlady was abit of a nutter.  I don't mean that in afun, eccentric sort of kooky way, I mean she was a cleaning rota, post-its onmy TV, shouting at my friends sort of mental.
Anyway, I had spent most of theday writing an essay and I went downstairs to...