Preparations have begun for Rose's big day, but there are tensions on both sides of the family that threaten to derail proceedings.
Rosamund arrives at Downton following Edith's shock departure and a secret may be revealed; Rose is delighted to introduce Atticus and his parents to Downton for the first time.
Branson must make a difficult decision about Sarah; Simon returns to Downton to discuss the painting with Cora.
Robert and Cora's relationship is strained; Blake's scheming starts to come to fruition; Mary is unexpectedly pitted against her love rival.
Annie gets a job working with a stage psychic, there are repercussions to Mitchell and Lucy sleeping together and Sam has got a very important question for George.