I have a confession to make. Yesterday, I was responsible for the deaths of millions of Britons. What happened is that MI5 asked me to trail Mehan Asnik, a suspected terrorist, through the streets of London. He had escaped from our security services while infected with a plague virus. Tracking him on CCTV, I swear I had him but then, in the rush-hour bustle, lost him. When the secure mobile rang, it was Harry Pearce at Thames House, chewing me out for the slaughter that had been caused by my mistake.