One morning in 1939, producer David O. Selznick locked himself in his office with the director Victor Fleming and the writer Ben Hecht. Selznick told them they had one week to turn Margaret Mitchell’s “Gone With the Wind” into a screenplay. To judge by his new comedy about their frenzied, round-the-clock writing marathon, Ron Hutchinson knows full well the perils of fashioning existing material into a compelling script.

“Moonlight and Magnolias” is a situation – at best, a scenario – striving to be a play, and only occasionally succeeding. Selznick (Douglas Sills) has everything riding on this film’s success. His father-in-law, Louis B. Mayer, will see to that. When Selznick tries to convince Hecht (Matthew Arkin) to spend a week knocking the novel into shape, he sets the stakes this way: “No screenplay, no movie. No movie, no more Selznick Studios. I’m back working for my father-in-law. Ruin. Humiliation. Failure. In front of the whole world. You want that for me?” This personal appeal brings Hecht around. That, and 15 grand.

Having fired original director George Cukor, Selznick now drags Victor Fleming (David Rasche) into the room. He has been off shooting “The Wizard of Oz,” and informs the boss that he really must run, as he’s left “a hundred and sixteen Munchkins dead drunk in the corridors or fornicating in the urinals of the Culver Hotel.” Over both men’s objections, Selznick puts him to work with Hecht, the best rewrite man in the business. There will be no leaving, no sleeping, and no food besides bananas and peanuts – brain food, Selznick believed – until the script is complete.

Thus confined, Mr. Hutchinson’s characters spend an hour and a half staging variations on the opening scene. Somebody (or -bodies) wants to leave, somebody (or -bodies) must prevent this from happening. Should they write the script or should they not write the script? Selznick wants to write the script but Hecht does not want to write the script and Fleming wants to go home. Maybe they will not write the script? And so forth. There are diversions here and there. Hecht, it turns out, is the only person on the planet who hasn’t read “Gone With the Wind.” This leaves Selznick and Fleming no choice but to re-enact the decisive moments of the story for him. Mr. Rasche’s rendition of Melanie’s childbirth is particularly inspired.

Lynne Meadow’s production, which opened at Manhattan Theatre Club last night, sometimes manages to make you overlook the play’s round-and-round-we-go structure. The material might have lent itself to an up-tempo, high-sheen, Howard Hawks-style sprint. But Ms. Meadow forgoes heavy stylization, opting for straightforward naturalism. The best moments are the least comic ones. As exhaustion wears everyone down, and Selznick’s desperation grows, he delivers a paean to moviemaking. From Mr. Hutchinson’s pen, it’s a click or two above the customary Hollywood self-romance. (I’m not an idea guy, I’m a man of action; producers don’t have power, the little people do; only movies let the dead live again, etc., etc.) Delivered with admirable conviction by Mr. Sills, it somehow ennobles the whole business of moviemaking. Out of the show’s longueurs comes something genuinely compelling. In another medium, we’d call the speech Oscar bait.

As Victor Fleming, Mr. Rasche, an MTC favorite of late, gets to be his usual Raschean self: blond hair flopping, eyes darting, cracking a joke now and then, snide with a dash of raffish charm. The sharp Margo Skinner makes the most of her chances as Selznick’s harried secretary. But Mr. Arkin, so deeply felt in “Dinner With Friends” a few seasons back, seems miscast here. Novelist, playwright, screenwriter, and script doctor extraordinaire, Ben Hecht was “the great hack genius,” a Chicago newspaperman made good. Mr. Arkin doesn’t begin to convey the native toughness the role demands.

Mr. Arkin also suffers the brunt of Mr. Hutchinson’s attempt to shoehorn some Weighty Issues into the fun. Hecht’s devotion to worldwide Jewish causes gets plenty of airtime here. He also tries to convince Selznick and Fleming that their script needs to reflect certain advanced liberal ideas about equality and the like. The combination doesn’t just drag down the action, it turns Hecht into a bit of a scold. It’s hard to believe that this is the gentleman who co-wrote the acid valentine “The Front Page.”

The great ancestor of Mr. Hutchinson’s play is Kaufman and Hart’s “Once in a Lifetime.” What a marvel that even now, seven decades later, it remains the final word on the romantic lunacy of Hollywood. Yet “Moonlight and Magnolias” pales in comparison to a play much nearer at hand. Not much happens in “Orson’s Shadow,” either. But in its rich characterizations, balance of comedy and pathos, and, best of all, its captivating theatricality, Austin Pendleton’s play has set a very high bar this season for shows about what happens when egos collide.

Until May 8 (131 W. 55th Street, between Sixth and Seventh Avenues, 212-581-1212).