Case file · Series 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.

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. This is not a complete content advisory.

Why it matters

The apparent transparency of an online meeting only emphasises how much the school community has kept off camera.

A head teacher is killed during an online PTA meeting, making an argument about a cancelled fundraiser the opening piece of evidence.

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.

  • Grammar school
  • PTA
  • Family history
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.

Open the full research dossierProduction, cast, forensics, deaths and filming evidence

Credits, context and checked facts

The episode file

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 ledger6 episodes credited to Helen Jenkins
  • Director ledger8 episodes directed by Matt Carter
  • Release positionCase 144 of 144
  • Story characterDark · Grammar school · PTA
  • Location evidence1 exact screen-use match
The timeline is evidence

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.

Three settings, one history

The investigation moves between the grammar school, a PTA fundraiser dispute and a village shop as the shared past becomes visible.

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.

Selected episode credits

Guest cast on file

Selected profiles and published cast-list entries. Database records are linked individually; this is not a full transcription or an independent check against the end credits.

The performers behind this case

Core cast

Actor profiles for the detective, investigating partner and pathologist credited to this episode.

No freely reusable portrait located. A rights-cleared photograph can be added later.
Lead detective

Neil Dudgeon

John Barnaby · Detective Chief Inspector

An 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
No freely reusable portrait located. A rights-cleared photograph can be added later.
Investigating partner

Nick Hendrix

Jamie Winter · Detective Sergeant

An 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
Actor Annette Badland at BBC Elstree Centre in 2016
Photo: AnemoneProjectors · CC BY-SA 4.0 · displayed with a layout crop
Forensic support

Annette Badland

Dr Fleur Perkins · Police pathologist

An 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 source rows represent 3 people in the current ledger.

Break the seal: reveal the death ledger
  1. Estelle Hallis

    Murder · Stabbing or impalement

  2. Kara Hallis

    Murder · Other recorded death

  3. Dominic Mayhew

    Murder · Stabbing or impalement

Search the complete deaths index →

Real place → fictional identity

What was filmed where?

Stoke Poges, Buckinghamshire

Stoke Court

Used as: The manor-house exterior and grounds become Causton Grammar School.

Building identities are cross-checked against the Casebook's published filming-location references. A named match describes the part used on screen, not the whole village and not necessarily an interior.

Wider filming areas

Places connected to this file

Location research remains open.

No real-place link is published here until it can be tied to a specific, sourced screen use.