The Maguires arrange for Bobby to leave the U.K., but the plan goes awry en route to the airport. Katherine sends a threatening message to Marcella.

Her stalker’s latest threat leaves Marcella suspicious of Frank. After recognizing one of Bobby’s abductors in police records, she tracks him down.

Marcella recalls how Frank rescued and reprogrammed her 18 months earlier. When Stacey flees from the Maguires with her baby, Marcella must find her.

Finn uses Rory’s phobia to bully him into an alliance. Marcella confronts Frank with a discovery about his past. DCI Sangha learns of Stacey’s arrest.

Marcella’s latest blackout leaves her with an unexplained corpse. Wondering why DCI Sangha is still in Belfast, Jack decides to investigate on his own.

As Endeavour and Thursday deal with the heartbreak of Joan’s departure, a death at East Cowley Slipper Baths hurls Oxford’s Finest into their darkest adventure.

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.