LONDON — One day in the late 1960s, the novelist Edna O’Brien was strolling around London with Marlon Brando, with whom she had just spent a (chaste) night. “Are you a great writer?” Brando asked.

“I don’t know,” she replied, “but I intend to be.”

It’s a story that Ms. O’Brien, 85, the grande dame of Irish literature, recounts in her memoir, “Country Girl,” and it’s an ambition that many believe she has achieved, including Philip Roth, who put it this way in an email: “She is among the handful of most accomplished living writers in the English language.”

Her most recent novel, “The Little Red Chairs,” to be published by Little, Brown and Company on Tuesday in the United States, is partly set in Ms. O’Brien’s native Ireland, but its subject is far wider. The tale begins with a mysterious figure who arrives in a village on the west coast of Ireland, and sets himself up as a holistic healer. Doctor Vlad, as he is known, quickly becomes a subject of fascination in the village, not least to the childless, unhappily married Fidelma. His identity is soon clear; he is a Balkan war criminal in hiding, the author of appalling suffering.

The consequences of Doctor Vlad’s brief relationship with Fidelma are the subject of Ms. O’Brien’s novel. As she put it recently, “I wanted to take a dreadful situation and the havoc and harm that it yields, and show how it spirals out into the world at large.”