Case file · Series 12, Episode 6 · Season 12, Episode 6

The Creeper

A celebrated cat burglar raids Midsomer while a writer planning to expose the Chettham family is smothered on their estate.

The 60-second case card

Should I watch this one?

The theft mystery and murder inquiry overlap without becoming the same puzzle, giving Barnaby two kinds of secrecy to untangle.

Best for
Cat burglar · Country estate · Family secrets
Mood
Classic
Team
DCI Tom Barnaby with DS Ben Jones
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 theft mystery and murder inquiry overlap without becoming the same puzzle, giving Barnaby two kinds of secrecy to untangle.

The elusive Creeper carries out two daring burglaries in one night. On the Chettham estate, writer David Roper is then found smothered; he had been preparing a book that threatened to disclose damaging episodes in the family's past.

A second person who knew the Chetthams is shot in woodland, raising the stakes beyond stolen valuables. Barnaby and Jones must identify the burglar while also determining who fears publication enough to kill.

  • Cat burglar
  • Country estate
  • Family secrets
Break the seal: reveal the finding

Who was the killer in The Creeper? (spoiler)

The burglaries provide access and confusion, while the murders protect a Chettham family history intended for Roper's book. Barnaby separates the thief's aims from the killer's.

Spoiler-safe viewing companion

Three questions to carry into the episode

Three spoiler-safe questions for your rewatch.

  1. Place

    What does Chettham Park conceal?

  2. Theme

    Which details could have more than one meaning?

  3. Teamwork

    Watch DCI Tom Barnaby and DS Ben Jones: who notices what?

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More episode detailsProduction, cast, deaths and filming information

Credits, context and checked facts

Production and cast

TV series
Series 12
Episode number
Episode 6
Written by
Andrew Payne
Directed by
Renny Rye
Listed transmission date(s)
27 September 2009 27 January 2010
Reported filming period
February–March 2009
Detective
DCI Tom Barnaby
Partner
DS Ben Jones
Pathologist
Dr George Bullard · Barry Jackson
Principal setting
Chettham Park
Casebook tone
Classic

Sources accompany the production credits and filming links.

Fictional settings and real filming places are listed separately. Filming links include 0 mapped areas; 2 exact sites.

Credits and archive connections

  • Writer credits11 episodes credited to Andrew Payne
  • Director credits23 episodes directed by Renny Rye
  • Release positionCase 72 of 144
  • Story characterClassic · Cat burglar · Country estate
  • Location evidence2 exact screen-use matches
Chettham Park House

Polesden Lacey in Surrey supplies the principal country-house setting.

Two connected mysteries

The Creeper's identity and the family murders intersect, but the episode treats motive and opportunity as separate questions.

Credits follow the linked chronology. Dates can differ between territories. Consult original credits for story, teleplay and adaptation wording. External synopses may contain spoilers.

Selected episode credits

The Creeper cast

These selected cast entries link to their published profiles. They do not include every name shown in the end credits.

No freely reusable portrait located. A rights-cleared photograph can be added later.
Played David Roper

Rik Mayall

David Roper is part of the wealthy social circle unsettled by a burglar known as the Creeper. Mayall's performance brings abrasive comic energy to a case already full of status anxiety and family friction.

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Actor Jenny Agutter in 2022
Photo: IDMacpherson1964 · CC BY-SA 4.0 · Source · displayed with a layout crop
Played Lady Isobel Chettham

Jenny Agutter

Lady Isobel Chettham is a poised member of the landed family targeted by the Creeper. Agutter gives the household an effortless sense of history while the investigation exposes its more immediate pressures.

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The performers behind this case

Core cast

Follow the cast links for full actor and character guides.

Image credits identify the licence used. No programme publicity stills are reproduced.

Forensic team

Dr George Bullard

Credit
Resident pathologist
Played by
Barry Jackson
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Spoiler-controlled deaths

Deaths recorded in this case

2 people die in this case, according to the linked death record.

Break the seal: reveal the list of deaths
  1. David Roper

    Murder · Poisoning

    Performer check
  2. Dr. Sylvia Goring

    Murder · Gunshot

    Performer check
Break a second seal: reveal the verified killer
Series 12 · episode 6 · checked 15 September 2026

Who was the killer in The Creeper? (spoiler)

Elizabeth Chettham · Lady Isobel Chettham

Elizabeth and Isobel acted together to kill David Roper after he threatened to expose the Chettham family secret: Elizabeth supplied the painkillers and Isobel smothered him. Isobel later shot Dr Sylvia Goring, with Elizabeth acknowledging the shared purpose; Tallis Filby's separate Creeper burglaries are not treated as murders.

Verified motive

Elizabeth and Isobel acted to preserve the Chettham family secret that Harry Godbolt was Freddy's biological father, protecting Freddy's place in the family line and the provider they had secured for him. They killed Roper before his book could expose the truth and Goring after the surviving medical evidence threatened the same secret.

Verified important clue

Archive case 72 · checked 16 September 2026David Roper's recovered laptop and Godbolt transcripts

The prison interviews preserve Harry Godbolt's boast about his affair with Isobel and make Freddy's hidden parentage publishable; recovering the laptop from the Chetthams exposes why Roper was smothered and why Goring's falsified blood results made her the next threat, while leaving the Creeper burglaries separate.

Verified decisive clue

Archive case 72 · checked 17 September 2026David Roper's recovered laptop and Godbolt transcripts

The prison interviews preserve Harry Godbolt's claim that he fathered Freddy and make the Chettham secret publishable. Recovering the laptop exposes why Elizabeth and Isobel silenced Roper and later Goring, while distinguishing their shared roles from Tallis Filby's unrelated Creeper burglaries.

Verified death and discovery order

Archive case 72 · checked 16 September 2026
  1. discovery
    Roper prepares to expose the Chettham secret

    David Roper's research threatens to reveal that Harry Godbolt, not Lord Chettham, was Freddy's biological father.

  2. death
    David Roper is drugged and smothered

    Elizabeth supplies painkillers and Isobel smothers Roper, acting together before his book can disclose the family secret.

  3. discovery
    The Creeper burglaries form a separate trail

    Tallis Filby's thefts explain the intrusions around the village but do not account for either murder.

  4. death
    Dr Sylvia Goring is shot

    Isobel kills the doctor after surviving medical evidence again threatens Freddy's place in the Chettham line.

  5. discovery
    The birth record restores the hidden parentage

    The surviving evidence connects Freddy to Harry Godbolt and supplies the common purpose behind the two deaths.

  6. discovery
    Elizabeth acknowledges their shared purpose

    The resolution separates Elizabeth's contribution to Roper's death from Isobel's physical acts while retaining both women as participants.

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Real place → fictional identity

Where was The Creeper filmed?

Leatherhead, Surrey

Polesden Lacey

Used as: The National Trust house becomes Chettham Park House.

Albury, Surrey

Albury Park

Used as: The estate appears as a Scottish Highlands manor in the closing sequence.

Sources accompany the identified filming places.

Wider filming areas

Places connected to this file

Location research remains open.

No real filming place is confirmed for this case.