One of the advantages of living where I do - heard an odd noise from outside, looked out, and there was Bittern.
It was pulling six or seven carriages out of Paddington Station. I think they do a couple of runs every weekend. More details here. Unfortunately the schedule of runs is out of date and I can't find anything more recent.
http://en.wikipedia.org/wiki/LNER_Class_A4_4464_Bittern What - you were expecting a bird?