Americans are transfixed by the aftermath of the September surprise in financial markets. Could there be a very different surprise coming in October?

The public thinks Democrats do better on economic issues, and the financial crisis erased the bounce in the polls that John McCain received from the Republican convention. After the second presidential debate, Mr Obama widened his lead, but dangers remain. Polls show that Republicans do better on the issue of terrorism. Last June, McCain adviser Charlie Black was reprimanded for having the temerity to point out that the intrusion of a terrorist event into the campaign would “certainly be a big advantage” for Mr McCain. Mr Black may have been politically incorrect but an objective analysis suggests he might be right.