CASEBOOK · SPOILER-LIGHT

London’s worst detective. London’s best unpaid younger brother.

By Does Your Duck Quack

The Diamond formula is gloriously unfair: Tim gets the office door and Nick gets the brains, the danger, the narration and almost none of the credit.

The brothers

HERBERT TIMOTHY “TIM” DIAMONDThe professional, technically

Nick’s adult brother and the nominal private detective. Tim is broke, impulsive, literal-minded and almost supernaturally able to choose the wrong explanation. His great comic gift is confidence without competence.

NICHOLAS “NICK” DIAMONDThe detective, actually

The younger brother, narrator and careful observer. Nick spots contradictions, endures Tim’s decisions and solves the cases while trying to survive criminals and adults who underestimate him.

PARTNERSHIP ENGINEDependence disguised as hierarchy

Tim provides legal adulthood, an office and access; Nick supplies judgment. Each case works because neither can quite operate alone.

SUPERFAN VERDICTWatson has hired Holmes

Except Watson insists he is Holmes, Holmes is a child, and the rent is overdue.

Reliable case chronology

Publication order is the cleanest reading route. The cases are largely self-contained, so “chronology” here does not invent exact dates between adventures.

Year / caseFormPlace in the shelf
1986The Falcon’s MalteserFull novelThe chocolate-box case that establishes Nick as narrator and actual detective.
1987Public Enemy Number TwoFull novelNick is sent into a young offenders’ prison to reach Johnny Powers.
1991South by South EastFull novel / screen-linked storyA murdered spy launches a train-and-Europe chase.
2003The Blurred ManShort bookA photograph and a supposedly dead philanthropist.
2003The French ConfectionShort bookA prize trip to Paris becomes a criminal chase.
2003I Know What You Did Last WednesdayShort bookAn island reunion turns into an elimination mystery.
2007The Greek Who Stole ChristmasShort bookA Christmas celebrity-protection case.
2011The Double Eagle Has LandedStandalone short storyA separate compact case, not one of the eight numbered shelf entries.
2022Where Seagulls DareFull novelThe long-awaited seaside return.

Novels, short books and collections

Full novels

The Falcon’s Malteser, Public Enemy Number Two, South by South East and Where Seagulls Dare.

Short books

The Blurred Man, The French Confection, I Know What You Did Last Wednesday and The Greek Who Stole Christmas.

Three of Diamonds

Collects The Blurred Man, The French Confection and I Know What You Did Last Wednesday.

Four of Diamonds

Collects those three compact cases plus The Greek Who Stole Christmas. It is a bind-up, not four new mysteries.

The Double Eagle Has Landed is separately catalogued short fiction. Counting unique cases prevents omnibuses from inflating the series total.

Just Ask for Diamond — film file

ProductionPrincipal creditsReading-room note
1988 UK featureUS TITLE: DIAMOND’S EDGEDirected by Stephen Bayly; screenplay by Anthony Horowitz; produced by Linda James; music by Trevor Jones; cinematography by Billy Williams.Based on The Falcon’s Malteser.
The brothersColin Dale as Nick; Dursley McLinden as Tim.They later reprise the roles for television.
EnsembleSaeed Jaffrey, Patricia Hodge, Roy Kinnear, Bill Paterson, Susannah York, Nickolas Grace, Peter Eyre and Jimmy Nail.The unusually rich comic cast gives the parody a recognisably British screen identity.
Film and novel comparison — reveal adaptation changes

The central engine remains the same: the brothers receive a suspicious chocolate box and discover that several dangerous people want it. The film condenses the novel into feature length, makes the visual disguises and criminal ensemble do work that Nick’s narration performs on the page, and foregrounds the brothers as a comic screen double act.

The US home-video title Diamond’s Edge is a release title, not a second adaptation. Edition runtimes and cuts should be checked separately rather than assumed identical.

South by South East — television file

The 1991 ITV/CITV production is a six-part sequel to the film, written and directed by Anthony Horowitz. Dursley McLinden and Colin Dale return as Tim and Nick; Monique van de Ven plays Charon. The production involved Red Rooster Films, IDTV, AVRO and TVS, with episodes running roughly 23–24 minutes.

The screen/book relationship is unusual: contemporary entries describe the television scripts and 1991 novel as closely linked, with the book treated as a novelisation in later accounts. This guide therefore avoids the simplistic label “TV adaptation of an already finished novel.”

The title-parody shelf

Diamond titleEchoesHow the joke works
The Falcon’s MalteserThe Maltese FalconA recognisable crime, thriller or popular-culture title is bent toward the case’s object, place or day.
South by South EastNorth by NorthwestA recognisable crime, thriller or popular-culture title is bent toward the case’s object, place or day.
The Blurred ManThe Third ManA recognisable crime, thriller or popular-culture title is bent toward the case’s object, place or day.
The French ConfectionThe French ConnectionA recognisable crime, thriller or popular-culture title is bent toward the case’s object, place or day.
I Know What You Did Last WednesdayI Know What You Did Last SummerA recognisable crime, thriller or popular-culture title is bent toward the case’s object, place or day.
The Greek Who Stole ChristmasHow the Grinch Stole ChristmasA recognisable crime, thriller or popular-culture title is bent toward the case’s object, place or day.
Where Seagulls DareWhere Eagles DareA recognisable crime, thriller or popular-culture title is bent toward the case’s object, place or day.
The Double Eagle Has LandedThe Eagle Has LandedA recognisable crime, thriller or popular-culture title is bent toward the case’s object, place or day.

Public Enemy Number Two also plays on the criminal-ranking phrase while making Nick share a cell with Public Enemy No. 1. The jokes signal genre affection: Horowitz is teasing the shelf, not standing outside it.

Recurring-joke catalogue

RUNNING GAGTim’s confidence

He is magnificently certain precisely when he has misunderstood the case.

RUNNING GAGNick’s invisible competence

Nick observes, deduces and rescues; adults still treat Tim as the professional.

RUNNING GAGThe office economy

Clients, rent and rewards expose how little glamour survives in a failing detective agency.

RUNNING GAGNames as punchlines

Characters and businesses frequently arrive already carrying a pun or genre reference.

RUNNING GAGHard-boiled narration

Nick borrows the rhythm of adult noir while reporting childish chaos and Tim’s disasters.

RUNNING GAGPolice impatience

Authority figures such as Snape have good reason to dread the Diamonds’ arrival.

RUNNING GAGTravel broadens Tim

Paris, islands, trains and seaside towns change the scenery, never his judgment.

RUNNING GAGDanger played straight

The villains can be real threats; comedy comes from the brothers’ response, not from pretending nothing matters.

Sources

Book order and premises use Anthony Horowitz’s official series pages; format and omnibus contents use the source-linked permanent entries and library catalogues. Screen credits use BFI-linked catalogue entries and corroborating production references.