|Ed Stoppard as Sir Hallam Holland and Keeley Hawes as Lady Agnes|
Holland - Photo: ©Nick Wall/BBC 2012 for MASTERPIECE
In the episode titled "The Love that Pays the Price," Lady Agnes catches the eye of charismatic American millionaire Caspar Landry but, as she and Sir Hallam look to their future, a tragic turn of events leaves their promised dreams - and a close family member - in jeopardy.
Downstairs, Mrs Thackeray makes a momentous decision, which throws the running of the house into chaos. Blanche and Mr Amanjit continue to clash, until a heart-breaking cause compels them to reconsider their differences.
Watch a sneak peek below: