Masterpiece Classic Sarah Bunting continues to cause waves above stairs, but this time she may have gone too far. On returning to Downton, Thomas is suffering from an inexplicable illness but Baxter suspects there is more to it than he is letting on... (more). Meanwhile, Violet reveals to Isobel the surprising truth of her past with Prince Kuragin and Mary comes to a decision concerning Lord Gillingham. When Rose’s father Shrimpie returns to Downton, he breaks some news that will shock the whole family.