The ghosts of the South Bank

Returning from a client in the Barbican this evening, I walked back from Embankment tube station to Waterloo. I thought I'd stop on the South Bank to get a few photos, but by this time it had started to rain, so didn't spend long. I was hoping to get ghosts of people walking through the photo, but as it was raining, there weren't that many people walking here, just in front of the festival hall. I hadn't noticed the girl in the middle of the photo however, who must have walked in stood still and walked out without me seeing / noticing her. Or perhaps she was a ghost?