© ITV Pic/Mark Bourdillon

Careful not to be seen, Samantha Berry slips away from Whitecombe Grange dressed in Georgian period attire on her way to a secret rendezvous. Unaware that a drone is filming her, she is stabbed to death by an unseen assailant.


With Kam away on a course, Barnaby and Winter meet locum pathologist Petra Antonescu. Clearly taken by Winter, she informs them that the victim was stabbed with a feather quill pen. Barnaby is puzzled to find a syringe lying nearby. Tracing Samantha to the Grange, Barnaby and Winter meet owners James and Kitty Oswood who explain they recently bought back Kitty's childhood home to host Jane Austin experience weekends. Winter learns from the Oswoods' rebellious daughter Polly that Samantha kept asking questions about the house and village. Local GP Solomon Franks, a guest at the event, was mysteriously absent at the time of the murder and Barnaby looks for connections. Samantha is found to be a journalist with a special interest in the village's new delivery service for prescriptions - by drone. Barnaby notes that her mobile is missing. As an unknown person watches drone footage of the murder, Barnaby tracks down Gemma Christie, a villager who runs a Jane Austin fan club in competition with the Oswoods. At her tea room, Gemma says she never met Samantha, but evidence suggests she is lying. Meanwhile Winter meets drone boss Doug Vaughan and pilot Ronin Chow who deny using cameras on their drones. That night at drone HQ, a mystery figure breaks in and sets fire to Ronin's laptop.....


The discovery that the destroyed laptop contained drone footage shines a light on Ronin's shady past. At the post-mortem, Petra reveals that Samantha was killed by poison and the syringe had traces of morphine. Barnaby interviews James' mother Mary Oswood, the pharmacist helping to run the drone trial, whose vague answers about the morphine only deepen his suspicions. Samantha's phone records take Winter to James' father, ex-headmaster Walter Oswood. His alibi for the murder forces doctor Solomon to come clean and admit to taking morphine for pain relief. As a drone delivers a secret package to the Grange, James receives a threatening e-mail - but what has he been caught doing?


Sarah attends the Georgian ball event at the Grange to help with her book research, while Barnaby finds Samantha's hidden mobile. When someone discharges a shotgun into the ballroom Winter gives chase, catching uninvited guest Gemma. She is not the culprit however, as evidence later points to Doug Vaughan. Winter discovers photos on Samantha's phone relating to a historical fire at the Grange and the man responsible - John Fullerton - who then went to prison. Winter finds out that Johnny was Samantha's father, providing a clue to Samantha's real motive for coming to the village. Barnaby catches Polly and Ronin smuggling contraband via drone. This leads Ronin to confess that he filmed Samantha's murder and suspects Ray Fryer, husband to Kitty's sister Neil, but it's clear he's got it wrong. Later something clicks for Ronin but before he can reveal anything he is murdered by a drone...


Ronin's murder directs the investigation towards Doug who is found guilty of blackmailing James over his secret affair with Ray Fryer. When Winter finds spy footage on Doug's computer, it gives Barnaby the final piece of the jigsaw. Racing towards the Grange, Barnaby and Winter find themselves playing with fire as they confront the killer......