Joseph O'Connor sets his brilliant novel, "Ghost Light" (Farrar, Straus & Giroux, 242 pages, $25), in two time frames and two places -- 1907 Dublin and 1952 London. He acknowledges the license his book takes with the documented lives of the two central characters. John Millington Synge was Ireland's most distinguished 20th-century playwright and a genius. Sickly all his life, Synge died from Hodgkin's disease at age 37. An actress named Molly Allgood, 14 years his junior, was his fiancée, and it is through her eyes, both as a rebellious young woman and as an alcoholic 67-year-old, that O'Connor depicts the scrupulously kind and gentle Synge.

The two could not have been more ill-suited. Well-educated, Synge comes from a Protestant landlord family. He possesses an extraordinary command of the language, and is as passionate about words as he is about the Irish landscape in all its manifestations. Born and raised Catholic in a Dublin slum, Molly is irreverent and flirtatious; her wit is quick and salty, and she "smokes like a soldier." Though uneducated, she is a talented and ambitious actress who would be cast as Pegeen in Synge's most celebrated play, the controversial "Playboy of the Western World."

Following Synge's failed chest surgery, he is an emotionally broken man. He and Molly go to a remote cottage deep in the Wicklow countryside. This clandestine interlude, which is drawn strictly from O'Connor's imagination, conveys the depth of their love and serves as the core of the novel. In reading this section we come to understand that by now Molly thinks of Synge as the source of whatever happiness and courage she commands.

When Synge dies, Molly copes by rationalizing: "Perhaps in its way it was also a liberation. The lonely island of the wifely years. ... The torn hopes darned, the shilling eked from the housekeeping and hidden away, the leavings reheated, the silences over supper, the clock watched late and the joint sliced thin -- like being buried together in the same coffin of politeness. ... It was not what I wanted with him."

Most of the novel portrays Molly at age 67 as she wanders drunkenly across London on her way to an evening appointment at the BBC. Here O'Connor employs second-person stream-of-consciousness narration, while he uses the more conventional omniscient narrator in composing the chapters set in 1907 Dublin. This blending of forms is remarkably successful. O'Connor makes all of Molly's disjointed, drunken thoughts compelling. One in particular stands out: "He always said you were over-imaginative, too given to fantasy. A Catholic trait, he would joke."

Beyond a doubt Synge believed in the Abbey Theater: It has "devoted itself to that class of people who have inherited nothing but their courage. It is they who are given flesh on our stage every night." Above all, he believed in the written word's possibilities. O'Connor's novel itself is an outstanding example of what the written word can achieve.

Katherine Bailey is a book critic in Bloomington. She is at