Avenue for an Assassin

Jonas Shaw, ex New York detective, ex-Winston Churchill spy, gets a call from France at his Cotswold manor near London.  An old World War II friend has a brother-in-law who is a cop in a tiny hamlet.  A routine traffic stop on a country road has turned out to be far from routine.  Can Jonas fly out to investigate?  The answer will lead to one of the bloodiest events in the history of Paris that will echo for years.