person right now but it's all really about the fightback this week. we're also finding out more about the sophistication that went into this plot. the police are hunting actually for one of isis' top french-speaking operatives that they believe directed the paris attacks. cnn's brian todd has more about this man. >> reporter: just hours after the carnage in paris, a claim of responsibility from isis' senior french operative, fabien clain. no attack in the 18th district every materialized, but a car believed to be driven by the alleged perpetrator salah abdeslam, was parked in the 18th district, he is still on the loose. the only suspected attacker believed to have survived. >> investigators believe to salah abdeslam may have been