Case file · Series 25, Episode 4 · Season 25, Episode 4
Top of the Class
A head teacher is killed during an online PTA meeting, making an argument about a cancelled fundraiser the opening piece of evidence.
Verified filming locations
Every filming site currently documented in this Casebook file is listed here. The published evidence does not establish a complete production itinerary.
- Stoke Court · Stoke Poges, Buckinghamshire
The manor-house exterior and grounds become Causton Grammar School.
Site guide → Filming source ↗
Map lookup by place name. A private house’s exact address is not marked.
Selected episode credits
Top of the Class cast
These selected cast entries link to their published profiles. They do not include every name shown in the end credits.
Fiona Dolman
Isabel Shaw
Mel Giedroyc
Denis Lawson
Georgie Glen
Kenny Doughty
Lucy Gaskell
Dean Fagan
Lorna Watson
Milo Twomey
Jake Kenny-Byrne
Lewis Griffin
James Vaughan
Sophie Roberts
Sophia Razvi
The 60-second case card
Should I watch this one?
The apparent transparency of an online meeting only emphasises how much the school community has kept off camera.
- Best for
- Grammar school · PTA · Family history
- Mood
- Dark
- Team
- DCI John Barnaby with DS Jamie Winter
- Spoiler guidance
- Read the premise freely; open the marked sections only after watching. Check the linked provider advisory for further viewing information.
Why it matters
The apparent transparency of an online meeting only emphasises how much the school community has kept off camera.
Causton Grammar head teacher Estelle Hallis is murdered while colleagues and parents are connected to a PTA meeting. A heated dispute over a cancelled fundraising appearance creates an obvious line of inquiry, but the unusual weapon and carefully framed timing suggest a more deliberate performance.
The discovery that Estelle's daughter died before her mother changes the order in which Barnaby and Winter must reconstruct events. A third killing inside a local shop connects school politics to an older personal history and to somebody determined to punish several members of the same circle.
Break the seal: reveal the finding
The apparently separate deaths form a planned sequence of revenge whose motive lies in a past account of responsibility rather than the immediate PTA dispute.
More episode detailsProduction, cast, deaths and filming information
Credits, context and checked facts
Production and cast
- TV series
- Series 25
- Episode number
- Episode 4
- Written by
- Helen Jenkins
- Directed by
- Matt Carter
- Listed transmission date(s)
- 29 December 2025
- Reported filming period
- June–July 2025
- Detective
- DCI John Barnaby
- Partner
- DS Jamie Winter
- Pathologist
- Dr Fleur Perkins · Annette Badland
- Principal setting
- Causton
- Casebook tone
- Dark
Check the credits, then follow the source trail for production and filming details. Counts below describe this archive’s records.
The fictional setting and the real filming sites are separate pieces of information. The location desk currently connects it to 0 broader filming areas and 1 exact on-screen site identity.
Credits and archive connections
- Writer credits6 episodes credited to Helen Jenkins
- Director credits8 episodes directed by Matt Carter
- Release positionCase 144 of 144
- Story characterDark · Grammar school · PTA
- Location evidence1 exact screen-use match
Fleur's examination establishes that Kara Hallis died before the murder witnessed during the PTA call, reversing the order in which the crimes become known.
The investigation moves between the grammar school, a PTA fundraiser dispute and a village shop as the shared past becomes visible.
Sources for the production file
Published episode chronology and credits ↗Official ITV programme page ↗Filming-location reference index ↗The chronology is the reference for the credits shown here. A programme homepage does not independently verify a filming date or every production detail. Where multiple transmission dates are listed, territory attribution needs checking. Story, teleplay and adaptation distinctions require the original credit wording; links to external synopses may reveal plot details.
The performers behind this case
Core cast
Actor profiles for the detective, investigating partner and pathologist credited to this episode.
Neil Dudgeon
John Barnaby · Detective Chief InspectorAn English actor whose television work before Causton included Piece of Cake, The Mrs Bradley Mysteries, Messiah and the sitcom Life of Riley. He also appeared in Midsomer Murders years earlier as a different character in Garden of Death.
- Messiah
- Life of Riley
- The Mrs Bradley Mysteries
Nick Hendrix
Jamie Winter · Detective SergeantAn English actor trained at the University of Exeter and RADA. His theatre work includes the National Theatre, Old Vic and West End, while his screen credits include Black Mirror, Marcella, The Crown, Legend and Suffragette.
- Black Mirror
- Marcella
- The Crown
Annette Badland
Dr Fleur Perkins · Police pathologistAn award-winning English actor with an extensive career in theatre, television, film and radio. Her many recognisable roles include Doctor Who, EastEnders, Outlander, Bergerac and pub landlady Mae in Ted Lasso.
- Ted Lasso
- Doctor Who
- EastEnders
Portraits are used only where a reusable licence or public-domain release has been verified. Publicity stills and stock photographs are not copied into this independent guide.
Forensic desk
Dr Fleur Perkins
- Credit
- Resident pathologist
- Played by
- Annette Badland
Fleur pairs forensic certainty with dry humour and a magnificently low tolerance for Midsomer nonsense.
Meet the Casebook pathologists →Spoiler-controlled deaths desk
Deaths recorded in this case
3 people die in this case, according to the linked death record.
Break the seal: reveal the death ledger
- Estelle Hallis
Murder · Stabbing or impalement
Performer check- Estelle Hallis: Mel Giedroyc
- Kara Hallis
Murder · Other recorded death
Performer check- Kara Hallis: Sophia Razvi
- Dominic Mayhew
Murder · Stabbing or impalement
Performer check- Dominic Mayhew: Jake Kenny-Byrne
Break a second seal: reveal the verified killer
Verified killer
Tim CrawfordTim pushed abusive headmaster Vincent Bell from a cliff at the outdoor centre years earlier, then killed Kara Hallis, Estelle Hallis and Dominic Mayhew when the recovered globe and their deductions threatened to expose him. His planned attack on Holly Randell was interrupted.
Verified motive
Tim killed former headmaster Vincent Bell in anger over years of sadistic abuse, believing only he could make Bell face consequences. Nineteen years later he killed Kara after she connected him to Bell and intended to go to police, killed Estelle after misreading Kara's message as evidence that she knew, and killed Dominic when he recognised the globe's link; Holly was the interrupted next target.
Real place → fictional identity
What was filmed where?
Stoke Court
Used as: The manor-house exterior and grounds become Causton Grammar School.
Sources support the listed site uses; they do not establish every filming location in an episode.
Wider filming areas
Places connected to this file
No real-place link is published here until it can be tied to a specific, sourced screen use.