Other Agatha Christie Novels
Periodically, Agatha Christie deserted her established sleuths such as Poirot and Marple and wrote novels with entirely new characters or else characters who appeared in other books in supporting roles. Sometimes, the stories were entirely standalone books.
The Tommy and Tuppence Novels
The Secret Adversay
Partners in Crime
N or M?
By the pricking of my thumbs
Below is a list of standalone novels
The Sittaford Mystery (1931)
Why didn't they ask Evans? (1934)
And Then There Were None (1939)
Death comes as the end (1944)
Crooked House (1949)
They came to Baghdad (1951)
Destination Unknown (1954)
Ordeal by Innocence (1958)
The Pale Horse (1961)
Endless Night (1967)
13 at Dinner (1969)
Passenger to Frankkfurt (1970)