A serial killer strikes with an ancient sword when the Causton Chamber of Commerce takes a bus trip to Brighton.
Miller is struggling to control her sister Lucy amid family tensions, Alec must confront his demons, and Mark Latimer has to make a decision.
Ellie tries to wrest back control, and time is running out for Alec Hardy. Meanwhile, Beth has to face an emotional ordeal alone.
Decisions are made, truths are revealed, and lives in Broadchurch are changed forever.
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. Meanwhile, downstairs, Mrs Thackeray makes a momentous decision, which throws the running of the house into chaos, and Blanche and Mr Amanjit continue to clash.
