S5, E4: Sarah Bunting continues to cause waves above stairs, but this time she may have gone too far. On returning to Downton, Thomas is suffering an inexplicable illness; Baxter suspects there’s more to it than he’s letting on. Meanwhile, Violet reveals to Isobel the surprising truth of her past with Prince Kuragin and Mary comes to a decision concerning Lord Gillingham, but things don’t go quite as planned. When Rose’s father Shrimpie returns to Downton, he breaks news that will shock the whole family.