© ITV/Mark Bourdillon

Bentham DeQuetteville falls to his death from the roof of Quitewell Hall after seeing a headless horseman, but his aristocratic family seem more concerned about their forthcoming Civil War re-enactment than the tragedy. Betty, estate manager and second wife of Toby DeQuetteville, wants to find ways to gain income for the ancestral seat, not helped much by the eccentric head of the family Sir Ludo and his wife Lady Izzy.


Barnaby finds a priest hole containing a 17th century portrait of headless Cavalier officer Geoffrey DeQuetteville on a grey horse. Toby's identical twin Julian tells detectives about a family legend - if the ghost of Geoffrey points at you it means you will die. Toby's son Simon blames the ghost for his mother's death in a riding accident years earlier. He has been struck dumb ever since.


The DeQuetteville's wealthy neighbours, Roundhead descendant Harry Fleetwood and his wife Sasha are being driven mad by the Civil War battles, especially as the DeQuettevilles corrupt history by changing the battle's outcome in favour of the Cavaliers.


When Julian refuses to sell Long Meadow to Sasha, she persuades him to put it up as a wager instead. If the Roundheads win the battle, they'll get the land. Then she pays glamorous stable owner Amanda Harding to hire her horses only to the Fleetwoods.


Julian takes his horse and carriage out but is lured down a country lane by the headless horseman. Later his dead body is found in his carriage - it's murder. His widow Diana admits her husband was no angel and had plenty of enemies.


A terrified Ludo spots the headless horseman outside Quitewell Hall pointing at him and is terrified he will be next. Diana flirts with Harry, hinting he could get his hands on the whole estate by marrying her. And Jones discovers Betty once worked for a branch of the DeQuetteville family in Norfolk - where a cousin also died in a riding accident.


Sarah Barnaby is the commentator at the Civil War battle but gets angry when the re-enactment veers wildly away from history. In the midst of the chaos, Ludo is lured outside the hall and killed by a falling gargoyle. The Fleetwoods give up their claim to the land.


Toby sees the rider next, and is locked in the house and guarded by the police. Jones discovers Amanda once had a grey horse. He dashes to Badgers Mill to track it down and finds Barnaby in pursuit of a motorbike. A gun is fired and the police arrive to find the motorcyclist gone and a plastic headless torso, shot at - but empty.


Barnaby and Jones discover the identity of the Headless Horseman and rush to Quitewell Hall in search of the murderer and some answers. Who is killing off the DeQuettevilles - and where is Simon?