“Richard wrote a diary entry in his head.Dear Diary, he began. On Friday I had a job, a fiancée, a home, and a life that made sense. (Well, as much as any life makes sense). Then I found an injured girl bleeding on the pavement, and I tried to be a Good Samaritan. Now I've got no fiancée, no home, no job, and I'm walking around a couple of hundred feet under the streets of London with the projected life expectancy of a suicidal fruitfly.”