Director Jack O’Brien currently has a new Broadway production. He also is in rehearsal with another Broadway venture. This is not surprising; Mr. O’Brien is one of the busiest theatre directors in America. What is unusual is that the show in performance and the one in rehearsal are the same play.

Well, sort of. Mr. O’Brien is in the midst of a six-month commitment to the American premiere of “The Coast of Utopia,” Tom Stoppard’s heady three-part examination of 19th-century Russian thinkers. The first part, “Voyage,” began previews October 17 and will open November 27. Meanwhile, rehearsals began on November 2 for the second section, “Shipwreck,” which will start previews December 5.

“The first one hasn’t really been seen by the press and we’re already starting work on the second,” Mr. O’Brien said. Despite his pressing situation, Mr. O’Brien sounded more chipper than anxious. Actually, he sounded chipper and anxious at the same time, and always does. “What was very interesting is we had been all through it in September. We did the text work on all three plays. Then we put that away and went to work on the first one.”

All those “we’s” refer to his 44-member cast, a gathering the size of which no other Broadway play and few musicals can boast. “[Director and choreographer] Jerry Mitchell and I are laughing about it,”said Mr. O’Brien, mentioning his collaborator on “Hairspray.” “He’s about to go into rehearsal for the musical ‘Legally Blonde,’ and we have more people in ‘The Coast of Utopia!’ Unbelievable.” (The trilogy’s $7.5 million budget is also musical-sized.)

Mr. O’Brien’s journey on the great ship Stoppard began in 2002 when he and British set designer Bob Crowley saw the trilogy’s world premiere at the Royal National Theatre. At the time, he, like most Americans, knew nothing of the vital chunk of Russian history (1835–1865) Stoppard whips to life for nearly eight hours. “Leave it to Tom. What can I tell you?” Mr. O’Brien said with a laugh.” Turgenev. Yeah, that’s the name you know. But Michael Bakunin, Alexander Herzen, Nicholas Ogarev — we don’t know any of those people. And of course what happens to these people and their lives is just unbelievable.”

Those four figures, along with literary critic Vissarion Belinsky, make up the central quintet in Stoppard’s epic. Thinkers, theorists, poets, and firebrands, they struggle and strive to drag their cumbersome, backward, Czarruled, serf-dependant homeland into the modern world, asking themselves, as one character puts it, “How did Russia become the Caliban of Europe?”

As soon as Lincoln Center tapped Mr. O’Brien for the job of staging the New York premiere, he began recruiting. Among those he drafted were Mr. Crowley, who in turn asked to share the burden with set designer Scott Pask; costume designer Catherine Zuber; lighting designers Brian MacDevitt, Kenneth Posner, and Natasha Katz — and some of the best young, male theater actors of the day — Brian F. O’Byrne, Billy Crudup, Ethan Hawke, Jason Butler Harner, Josh Hamilton, David Harbour — most of whom now exhibit various manifestations of facial hair, in keeping with the hirsute European fashions of the time. With the exception of Richard Easton, who plays the father of the Hawke character, none of the actors had any experience with the repertory model, in which one play is rehearsed while another is performed.

“The more the merrier,” Mr. O’Brien said of his creative brood. “I love a lot of creative egos around me. I love big powerful imaginations. I don’t find it remotely claustrophobic or threatening.I love communal living.I get turned on by being surrounded by a lot of yapping imaginations.”

To prep his troupe, Mr. O’Brien implored his actors to read the E.H. Carr history, “The Romantic Exiles.” Some of the cast members did one better, flying off to the homeland of those exiles, an impetuous expedition that the seasoned Mr. O’Brien referred to as “adorable.”

Once everything and everybody was in place, the director began to attend to his vision of the sprawling history. “When the penny really dropped for me — after four years of studying with Tom and Crowley and everybody and trying to wrap my mind around what this was and how to tell it and how to approach it — I suddenly realized the secret for me was in the title. There is no coast to Utopia. You can’t get there,” he said.

“And then there’s the idea of water and a drowning in the second piece, which is central to Herzen’s story.” Though he doesn’t make an appearance until the second act of “Voyage,” Alexander Herzen, an influential writer and intellectual who spent much of his life in exile from Russia, is a pivotal figure in Mr. Stoppard’s play. O’Brien knew he had to clue the audience in to his importance, so he created an unscripted image at the top of the production in which a despairing Herzen slumps in a chair, seemingly suspended in midair and surrounded by billowing blue cloth made to resemble roiling waters. That striking stage picture will reoccur at the beginning of both “Shipwreck” and “Salvage,” the trilogy’s final segment.

Mr. O’Brien’s time at the wheel of “The Coast of Utopia”will officially end on February 15, 2007, when “Salvage” opens. Then it’s off for a 10-day cruise around Costa Rica on a masted cruiser, and, after that, back to New York — and another trilogy. Unbelievably, the director has found a way to top his work on Mr. Stoppard’s play in the same season. In April, he will make his directorial debut at the Metropolitan Opera with a new production of Puccini’s “Il Trittico.”

As Mr. O’Brien said of himself, “It certainly is Jack’s year for trilogies.”