Producers of hit US show Lost are discussing an end date for the series, so they can plan for future episodes. They insist the cult drama, about a group of people stranded on a mystery island after a plane crash, is not set to end soon, however an end date will ensure the series doesn't outstay its welcome. Executive producer CARLTON CUSE says, "Once we figure out when that will be, a lot of the questions will go away." Viewing figures are said to have dropped dramatically since the first series, however the show's creators insist this is deceptive because Lost was "a sensation" during its first and second seasons. Bosses say they have taken lessons from nineties hit series THE X-FILES, which garnered its best ratings during the middle of that decade, but ran until 2002. Cuse adds, "That was a great show that probably ran two seasons too long. That is a cautionary tale for us."