Carolyn Wells
Carolyn Wells Houghton
Fleming Stone, a bookish private investigator, frequently called in to help the police solve a crime, in New York City1:

The Clue (1909)

The Gold Bag (1911)

A Chain of Evidence (1912)

The Maxwell Mystery (1913)

Anybody But Anne (1914)

The White Alley (1915)

The Curved Blades (1916)

The Mark of Cain (1917)

Vicky Van (1918)
APA: The Elusive Vicky Van (1934)

The Diamond Pin (1919)

Raspberry Jam (1920)

The Mystery of the Sycamore (1921)

The Mystery Girl (1922)

Feathers Left Around (1923)

Spooky Hollow (1923)

The Furthest Fury (1924)

Prillilgirl (1924)

Anything But the Truth (1925)

The Daughter of the House (1925)

The Bronze Hand (1926)

The Red-Haired Girl (1926)

All at Sea (1927)

Where’s Emily (1927)

The Crime in the Crypt (1928)

The Tannahill Tangle (1928)

The Tapestry Room Murder (1929)

Triple Murder (1929)

The Doomed Five (1930)

The Ghosts’ High Noon (1930)

Horror House (1931)

The Umbrella Murder (1931)

Fuller’s Earth (1932)

The Roll-Top Desk Mystery (1932)

The Broken O (1933)

The Clue of the Eyelash (1933)

The Master Murderer (1933)

Eyes in the Wall (1934)

The Visiting Villain (1934)

The Beautiful Derelict (1935)

For Goodness’ Sake (1935)

The Wooden Indian (1935)

The Huddle (1936)

In the Tiger’s Cage (1936)

Money Musk (1936)

Murder in the Bookshop (1936)

The Mystery of the Tarn (1937)

The Radio Studio Murder (1937)

Gilt-Edged Guilt (1938)

The Killer (1938)

The Missing Link (1938)

Calling All Suspects (1939)

Crime Tears On (1939)

The Importance of Being Murdered (1939)

Crime Incarnate (1940)

Devil’s Work (1940)

Murder on Parade (1940)

Murder Plus (1940)

The Black Night Murders (1941)

Murder at the Casino (1941)

Murder Will In2 (1942)

Who Killed Caldwell? (1942)

Alan Ford, a connoisseur and gentleman private investigator, in New York City:

The Bride of a Moment (1916)

Faulkner’s Folly (1917)

Pennington “Penny” Wise, a psychic private investigator, and his female sidekick Zizi, in New York City and New England:

The Room with the Tassels3 (1918)

The Man Who Fell Through the Earth (1919)

In the Onyx Lobby (1920)

The Come-Back (1921)

The Luminous Face (1921)

The Vanishing of Betty Varian (1922)

The Affair at Flower Acres (1923)

Wheels Within Wheels (1923)

Lorimer Lane, in New York City:

More Lives Than One (1923)

The Fourteenth Key (1924)

Kenneth Carlisle, in New York and Connecticut:

Sleeping Dogs (1929)

The Doorstep Murders (1930)

The Skeleton at the Feast (1931)


The Disappearance of Kimball Webb4 (1920)

The Moss Mystery (1924)

Face Cards (1925)

The Vanity Case (1926)

The Sixth Commandment (1927)

Deep Lake Mystery (1928)