Agatha Christie's fictional universe

In Agatha Christie's novels several characters cross over different sagas, creating a fictional universe in which most of her stories are set. The most notable example is the novel The Pale Horse, which features Ariadne Oliver, Major Despard and his wife Rhoda (all had previously appeared on Cards on the Table) and Mrs Dane Calthrop (from The Moving Finger).^[1]

List of cross-overs

Crossovers by Christie

Story	Length	Year	Crossing-over characters
The Mystery of the Blue Train	Novel	1928	Hercule Poirot, Katherine Grey (who lives in St. Mary Mead)
The Case of the Discontented Soldier	Short story	1932	Parker Pyne, Ariadne Oliver, Miss Lemon[2]
The Case of the Middle-aged Wife	Short story	1932	Parker Pyne, Miss Lemon
The Second Gong	Short story	1932	Hercule Poirot, Mr. Satterthwaite
Three Act Tragedy	Novel	1934	Hercule Poirot, Mr. Satterthwaite
Cards on the Table	Novel	1936	Hercule Poirot, Ariadne Oliver, Superintendent Battle, Colonel Race, Colonel Despard, Rhoda Despard[3]
Death on the Nile	Novel	1937	Hercule Poirot, Colonel Race
The Moving Finger	Novel	1942	Miss Marple, Mrs Dane Calthrop, Rev Dane Calthrop
Towards Zero	Novel	1944	Superintendent Battle, Hercule Poirot (mentioned)
The Labours of Hercules	Collection of related short stories	1947	Hercule Poirot, Miss Lemon, Sherlock and Mycroft Holmes (mentioned)
Mrs McGinty's Dead	Novel	1952	Hercule Poirot, Ariadne Oliver
Hickory Dickory Dock	Novel	1955	Hercule Poirot, Miss Lemon
Dead Man's Folly	Novel	1956	Hercule Poirot, Ariadne Oliver, Miss Lemon
Cat Among the Pigeons	Novel	1959	Hercule Poirot, Mr. Robinson, Colonel Pikeaway
The Pale Horse	Novel	1961	Ariadne Oliver, Colonel Despard, Rhoda Despard, Mrs Dane Calthrop, Rev Dane Calthrop
The Clocks	Novel	1963	Hercule Poirot, Superintendent Battle (mentioned)
At Bertram's Hotel	Novel	1965	Miss Marple, Mr. Robinson
Third Girl	Novel	1966	Hercule Poirot, Ariadne Oliver, Miss Lemon
Hallowe'en Party	Novel	1969	Hercule Poirot, Ariadne Oliver
Passenger to Frankfurt	Novel	1970	Mr. Robinson, Colonel Pikeaway
Elephants Can Remember	Novel	1972	Hercule Poirot, Ariadne Oliver, Miss Lemon
Postern of Fate	Novel	1973	Tommy and Tuppence, Mr. Robinson, Colonel Pikeaway
Hercule Poirot and the Greenshore Folly	Novella	2013	Hercule Poirot, Ariadne Oliver, Miss Lemon

Crossovers by others

Outside of stories by Christie herself, adaptations of her works have also featured crossovers:

• The Alphabet Murders in 1966 featured a meeting between Poirot and Marple where they exchange glances
• Agatha Christie's Great Detectives Poirot and Marple, a 2004 anime series, connects the two
• the 2006 adaptation of By the Pricking of My Thumbs as episode 7 (season 2 episode 3) of Agatha Christie's Marple has Marple meet Tuppence while Tommy is away

Other stories

Hercule Poirot

• The Mysterious Affair at Styles (1920 novel)
• The Adventure of the Western Star (1923 short story)
• The Tragedy at Marsdon Manor (1923 short story)
• The Adventure of the Cheap Flat (1923 short story)
• The Mystery of Hunter's Lodge (1923 short story)
• The Million Dollar Bond Robbery (1923 short story)
• The Adventure of the Egyptian Tomb (1923 short story)
• The Jewel Robbery at the Grand Metropolitan (1923 short story)
• The Kidnapped Prime Minister (1923 short story)
• The Disappearance of Mr Davenheim (1923 short story)
• The Adventure of the Italian Nobleman (1923 short story)
• The Case of the Missing Will (1923 short story)
• Christmas Adventure (1923 short story)
• The Affair at the Victory Ball (1923 short story)
• The Adventure of the Clapham Cook (1923 short story)
• The Cornish Mystery (1923 short story)
• The Adventure of Johnnie Waverly (1923 short story)
• The Double Clue (1923 short story)
• The King of Clubs (1923 short story)
• The LeMesurier Inheritance (1923 short story)
• The Lost Mine (1923 short story)
• The Plymouth Express (1923 short story)
• The Chocolate Box (1923 short story)
• The Veiled Lady (1923 short story)
• The Submarine Plans (1923 short story)
• The Market Basing Mystery (1923 short story)
• The Murder on the Links (1923 novel)
• The Murder of Roger Ackroyd (1926 novel)
• The Under Dog (1926 short story)
• Four and Twenty Blackbirds (1926 short story)
• The Big Four (1927 novel)
• Double Sin (1928 short story)
• Wasp's Nest (1928 short story)
• Alibi (1928 play)
• The Third Floor Flat (1929 short story)
• Black Coffee (1930 play)
• Peril at End House (1932 novel)
• The Mystery of the Bagdad Chest (1932 short story)
• Lord Edgware Dies (1933 novel)
• Murder on the Orient Express (1934 novel)
• Death in the Clouds (1935 novel)
• How Does Your Garden Grow? (1935 short story)
• The A.B.C. Murders (1936 novel)
• Murder in Mesopotamia (1936 novel)
• Murder in the Mews (1936 novella)
• Triangle at Rhodes (1936 novella)
• Problem at Sea (1936 short story)
• Poirot and the Regatta Mystery (1936 short story)
• The Incredible Theft (1937 novella)
• Dead Man's Mirror (1937 novella)
• Yellow Iris (1937 short story)
• The Dream (1937 short story)
• Dumb Witness (1937 novel)
• Wasp's Nest (1937 TV play)
• The Yellow Iris (1937 radio play)
• Appointment with Death (1938 novel)
• Hercule Poirot's Christmas (1938 novel)
• The Dream (1938 short story)
• Sad Cypress (1940 novel)
• One, Two, Buckle My Shoe (1940 novel)
• Evil Under the Sun (1941 novel)
• Five Little Pigs (1942 novel)
• The Hollow (1946 novel)
• Taken at the Flood (1948 novel)
• After the Funeral (1953 novel)
• The Adventure of the Christmas Pudding (1960 novella)
• The Mystery of the Spanish Chest (1960 novella)
• Curtain (1975 novel)
• The Incident of the Dog's Ball (2010 short story)
• The Capture of Cerberus (2010 short story)

Miss Marple

• The Tuesday Night Club (1927 short story)
• Ingots of Gold (1928 short story)
• The Blood-Stained Pavement (1928 short story)
• The Idol House of Astarte (1928 short story)
• Motive v. Opportunity (1928 short story)
• The Thumb Mark of St. Peter (1928 short story)
• The Blue Geranium (1929 short story)
• The Companion (1930 short story)
• The Four Suspects (1930 short story)
• A Christmas Tragedy (1930 short story)
• The Herb of Death (1930 short story)
• The Affair at the Bungalow (1930 short story)
• Death by Drowning (1930 short story)
• The Murder at the Vicarage (1930 novel)
• Miss Marple Tells a Story (1934 short story)
• The Case of the Caretaker (1941 short story)
• The Tape-Measure Murder (1942 short story)
• The Case of the Perfect Maid (1942 short story)
• The Body in the Library (1942 novel)
• Strange Jest (1944 short story)
• A Murder is Announced (1950 novel)
• They Do It with Mirrors (1952 novel)
• A Pocket Full of Rye (1953 novel)
• Sanctuary (1954 short story)
• 4.50 from Paddington (1957 novel)
• The Dressmaker's Doll (1958 short story)
• Greenshaw's Folly (1960 short story)
• The Mirror Crack'd from Side to Side (1962 novel)
• A Caribbean Mystery (1964 novel)
• Nemesis (1971 novel)
• Sleeping Murder (1976 novel)

Mr. Satterthwaite

• The Coming of Mr Quin (1924 short story)
• The Shadow on the Glass (1924 short story)
• At the "Bells and Motley" (1925 short story)
• The Sign in the Sky (1925 short story)
• The Love Detectives (1926 short story)
• The Soul of the Croupier (1927 short story)
• The Voice in the Dark (1927 short story)
• The Face of Helen (1927 short story)
• The Dead Harlequin (1927 short story)
• The Bird with the Broken Wing (1927 short story)
• The World's End (1927 short story)
• Harlequin's Lane (1927 short story)
• The Man from the Sea (1929 short story)
• The Harlequin Tea Set (1971 short story)

Parker Pyne

• The Case of the Distressed Lady (1932 short story)
• The Case of the Discontented Husband (1932 short story)
• The Case of the City Clerk (1932 short story)
• The Case of the Rich Woman (1932 short story)
• Have You Got Everything You Want? (1933 short story)
• The Gate of Baghdad (1933 short story)
• The House at Shiraz (1933 short story)
• The Pearl of Price (1933 short story)
• Death on the Nile (1933 short story)
• The Oracle at Delphi (1933 short story)
• Problem at Pollensa Bay (1936 short story)
• The Regatta Mystery (1939 short story)

Superintendent Battle

• The Secret of Chimneys (1925 novel)
• The Seven Dials Mystery (1929 novel)
• Murder is Easy (1939 novel)
• Towards Zero (1956 play adaption)
• Chimneys (2003 play adaption)

Tommy and Tuppence

• The Secret Adversary (1922 novel)
• Partners in Crime (1929 collection of related short stories)
• N or M? (1941 novel)
• By the Pricking of My Thumbs (1968 novel)

Colonel Race

• The Man in the Brown Suit (1924 novel)
• Sparkling Cyanide (1945 novel)

Notes

1. Fictional World of Agatha Christie
2. Ariadne Oliver
3. Ariadne Oliver