Cora's tries to set up Mary with Evelyn Napier, who falls for his friend instead, with significant consequences for the household. Bates takes action to help cure his limp.

The Great War unsettles life at Downton and surprising news about Matthew rocks the family. New maid Ethel irritates O'Brien - and Bates returns with devastating news for Anna.

Carson is finding it tough maintaining standards in the house, and the suicide of a young officer prompts Isobel to suggest converting Downton Abbey into a convalescent hospital.