Imaginary Friends, the new play by Nora Ephron about the literary and personal feud between novelist-critic Mary McCarthy and playwright-memoirist Lillian Hellman, may very possibly include, as major characters, more members of 20th century intellectual circles than any play in Broadway history.

Among the heady names to parade through the "play with music" are literary critic Edmund Wilson, Partisan Review co-founder Philip Rahv, novelist Dashiell Hammett, poet and essayist Stephen Spender, novelist James T. Farrell and, for a second, Norman Mailer (all played on the stage by Harry Groener).

For those theatregoers somewhat removed from their English Lit 101 college courses and wishing for a refresher course on the history of 20th century letters, the following thumbnail sketches are offered:

Dashiell Hammett (1894-1961): The author of the classic detective novels "The Maltese Falcon," "The Glass Key" and "The Thin Man." He was a heavy drinker and smoker and politically active. In 1951, he was named a Communist before the House Un-American Activities Committee and was blacklisted. Hammett and Hellman became companions in the early '30s and his support of her was crucial to her success as a playwright. (Nick and Nora Charles, from "The Thin Man," are based in part on Hammett and Hellman.) He suffered from tuberculosis and wrote little during the last years of his life. He died at Hellman's Manhattan townhouse.

James T. Farrell (1904-79): Best known today as the author of the trilogy "Studs Lonigan." He wrote 25 novels of gritty realism, five centering around the character of Danny O'Neill, and most set in his native Chicago. He fiercely advocated leftist politics during the 1930s and '40s and was friendly with the Partisan Review crowd. It was at a party at Farrell's apartment that McCarthy was introduced to Communism. Philip Rahv (1908-73): Co-founder in 1937 with William Phillips of The Partisan Review, a towering literary magazine with leftish leaning and a pro-Communist, anti Stanlinist political viewpoint. The Review reclaimed writing and art as a force unto itself, and was opposed to its use as a tool for political means. Among the writers to contribute to the publication (which still operates, though to considerably less influence) were Hannah Arendt, James Baldwin, F.W. Dupee, James T. Farrell, Andre Gide, Clement Greenberg, Irving Howe, Dwight MacDonald, Norman Mailer, George Orwell, Norman Podhoretz, Susan Sontag, Stephen Spender, Diana Trilling, Lionel Trilling, Leon Trotsky and Mary McCarthy. Rahv lived with McCarthy for a time. The multi-lingual child of poor Russian-Jewish immigrants, Rahv joined the Communist Party in the 1930s. He changed his named from Greenberg to Rahv, which means "Rabbi" in Hebrew.

Stephen Spender (1909-95): A London-born poet and critic, he ran with such other British literary lions as W. H. Auden, Christopher Isherwood and Cyril Connolly. With Connolly, he co-founded the literary magazine Horizon and was its editor from 1939 to 1941. He fought in the Spanish Civil War and fought for many social causes. His many books of poetry include "Twenty Poems," "Vienna," "The Still Centre," and "Poems of Dedication." He was knighted in 1983. Spender was at the center of a late-in-life scandal when novelist David Leavitt was accused of stealing material from Spender's autobiographical "World Within World" for his novel "While England Sleeps."

Edmund Wilson (1895-1972): Arguably the greatest American literary critic of the 20th century. A prominent figure in New York's writing scene from the 1910's on, Wilson was rare among critics in that he was universally respected, his good opinion sought by writers great and small. He was the literary editor of The New Republic and wrote much of his later work for The Nation. His many volumes of literary and social criticism included "To the Finland Station," about the roots of Communism; "The American Earthquake," a look at American during the Jazz Age and the Depression; "The Bit Between My Teeth," about the literary scene in the 1950s; "Classics and Commercials," about the scene in the 1940s; and the novel "I Thought of Daisy." He kept a diary throughout his life, much of it subsequently published. Though far from handsome, Wilson, who always wore brown suits, was a ladies' man, often courting the leading lady writers of the day, including poet Edna St. Vincent Millay. He was married to Mary McCarthy from 1938 to 1945. He was nicknamed "Bunny" because of his pink complexion.