Long before achieving literary fame with The Age of Innocence, the novelist Edith Wharton wrote a number of plays that never made it to the stage.

Two scholars have discovered one of them, a previously unknown work dating back to 1901, among a bunch of papers in an archive in Austin, Texas.

About 80 years after Wharton’s death, researchers have found a play titled The Shadow of a Doubt in the Harry Ransom Center at the University of Texas. Dr Laura Rattray and Prof Mary Chinery, from Glasgow University and Georgian Court University respectively, found two typescript copies of the play and have also established that it was in production by early 1901 with theatre producer Charles Frohman and Elsie de Wolfe in the leading role.

“The archives in the United States and Europe with huge holdings on this most transatlantic of authors have been extensively researched,” Rattray said. “After all this time, nobody thought there were long, full scale, completed, original, professional works by Wharton still out there that we didn’t know about. But evidently there are. In 2017, Edith Wharton continues to surprise.”

Title page of Edith Wharton’s typescript draft of The Shadow of a Doubt, 1901. Photograph: Courtesy Harry Ransom Center

Set in England, The Shadow of a Doubt centres on the character Kate Derwent, a former nurse married to a gentleman.

Opening on a scene of social privilege and affluence studded with sharp one-liners, the play takes a dark and controversial turn into a world of extortion, mistrust, deception and assisted dying.

Glasgow University said the discovery had generated excitement among scholars. Before Chinery came across an old news item about the 1901 production and its eventual postponement, Wharton scholars past and present had no knowledge of the play.

Character list for Edith Wharton’s typescript draft

It is not referenced in major Wharton biographies, and other plays are all unfinished manuscripts and typescripts held in the archives at Yale University.

Rattray said: “The late 19th and early years of the 20th century cover a pivotal, formative period of Wharton’s career, about which scholars still have less information than they would like.

“Well before the publication of her first novel, we can now ascertain that Wharton was establishing herself as a playwright, deeply engaged in both the creative and business aspects of the theatre – playwriting more important to her at this time than establishing herself as a novelist.

“Yet the discovery of The Shadow of a Doubt also develops new thinking and proves of profound influence on our understanding of Wharton’s work as a novelist.”

Born in 1862, Wharton won the Pulitzer prize for The Age of Innocence, published in 1920. She was also nominated three times for the Nobel prize in literature.

When The Shadow of a Doubt was written, Wharton, then 39, was not yet a novelist, and had published only shorter fiction and poetry.

Rattray and Chinery, who have published their findings in the new issue of the Edith Wharton Review, met last summer at a conference devoted to Wharton and decided to join forces.

Their discovery comes as academics found unseen work by another female literary giant. Poems by Sylvia Plath were deciphered in carbon paper hidden in the back of an old notebook, offering a glimpse of how the poet worked with her then husband, fellow poet Ted Hughes.