In this riveting special, DOWNTON ABBEY REVISITED, savor great moments from the series' first two seasons, along with cast interviews, rare behind-the-scenes footage and a sneak peek at what's in store for the Crawleys as they enter the Roaring Twenties. What will become of Bates? What new mischief will villainous footman Thomas and scheming lady's maid O'Brien instigate? Will wedding bells finally ring? And how will the formidable Dowager Countess (Dame Maggie Smith) handle the arrival of Lady Grantham's American mother (Shirley MacLaine)?