The first trailer for "Downton Abbey: The Grand Finale" is out now. The film is the third in the franchise and will be the conclusion to the story that started as TV series in 2010. It will follow Lady Mary as she takes part in London's high society. The cast includes Michelle Dockery, Hugh Bonneville, Elizabeth McGovern and Jim Carter. "Downton Abbey: The Grand Finale" hits theaters on September 12th.