I am standing in a quiet London street, just off a busy market, and nobody is coming to help me. The personal attack alarm I have set off screeches away into a void of nothingness.

Eventually, a man walks past on his mobile phone, glances in my direction and looks annoyed. A pigeon looks slightly alarmed.

I could be dead by now, I think. Or maimed. Damn you fellow citizens. "Why didn't you come and see if I was OK?"...