Here is an intriguing exercise: Consider the full trajectory of your life, and try to recall the person you were at about a dozen different moments along the way. As it happens, you might not recognize your younger self. And your older self might also be unrecognizable to you in its own way.

This, according to Tracy Letts, is the kernel of the idea that ultimately grew into his newest play, “Mary Page Marlowe,” which is about to receive its world premiere at Steppenwolf Theatre — the place where his 2008 Pulitzer Prize- and Tony Award-winning drama, “August: Osage County,” as well as “Superior Donuts” and ‘The Man from Nebraska,” also had their start.

The title character in Letts’ play is an accountant from Ohio. Born into a Catholic family in the mid-1940s, with a father who was a war veteran, Marlowe has led what might be called an ordinary life, and, as the playwright put it, “She has made many missteps along the way — some significant, some mundane — as she tried to figure out who she was and what she really wanted.”

Rebecca Spence in rehearsal at Steppenwolf Theatre for Tracy Letts' new play, "Mary Page Marlowe." (Photo: Joel Moorman)

Rebecca Spence in rehearsal at Steppenwolf Theatre for Tracy Letts’ new play, “Mary Page Marlowe.” (Photo: Joel Moorman)

Though the running time of the play is to be just about 90 minutes, it features an exceptionally large cast of 18, with seven actresses portraying Marlowe from infancy (with three babies alternating in that role), to the age of 69.

Caroline Heffernan, will play Mary at age 12, with Annie Munch as Mary at age 19; Carrie Coon (Letts’ wife, a veteran of Chicago and Broadway stages and may be most widely known for her role as Margo Dunne in the film “Gone Girl”) at ages 27 and 36; Rebecca Spence at ages 40 and 44; Laura T. Fisher at age 50;  and Tony Award-winner Blair Brown at ages 59, 63 and 69.

“Each of these actresses generally carries an entire play,” said Letts. “Here they will have just about 10 or 12 minutes each, which is its own challenge.”

‘MARY PAGE MARLOWE’
When: March 31 – May 29
Where: Steppenwolf Theatre, 1650 N. Halsted
Tickets: $20 – $89
Info: (312) 335-1650; www.steppenwolf.org

The initial work on “Mary Page Marlowe” began when Letts, who also is a Tony Award-winning actor, was in Capetown, South Africa, filming episodes of the hit Showtime series, “Homeland,” in which he played the role of Andrew Lockhart, a powerful  Senator from Indiana who went on to serve as director of the CIA.

“At the same time my mom [the novelist and teacher, Billie Letts] was very ill, and I got to go home and visit her before she passed away. It was a tough time. And when I got back to Capetown — where I was only shooting a couple of days a week, and don’t do the tourist thing —  I began writing the play. It’s not about my mom, but I did borrow elements of her life.”

When Letts first showed the play to Steppenwolf’s artistic director, Anna D. Shapiro (whose direction of “”August: Osage County” won her a Tony Award, too), she asked him: “Why did you decide to use a woman’s voice?”

“I told her: ‘I couldn’t have written this story if the character had been a man because it would have turned out to be more linear and fact-based. With a woman it could be emotion-based, and not bound by chronology. And I have to say, sitting in a rehearsal room with the 13 women in this play is pretty great. They have their own power, and I am lucky to have them in this play. Of course there are several men in Mary’s life, too.”

Playwright Tracy Letts watching Steppenwolf Theatre rehearsals for his new play, "Mary Page Marlowe. (Photo: Courtesy of Steppenwolf Theatre)

Playwright Tracy Letts watches Steppenwolf Theatre rehearsals for his new play, “Mary Page Marlowe.” (Photo: Courtesy of Steppenwolf Theatre)

As for how all the various aspects of Mary come together, just in terms of the logistics of flow and staging, Letts said that was still being worked out in rehearsal.

“But as I wrote the play I had the whole person in my head, and I knew the initial scene would be when Mary was telling her kids that she was getting divorced and they’d be moving to Kentucky. Creating Mary’s emotional map — the mixing and matching of the other scenes — took a long time. The one thing I knew was that I didn’t want her to be an ‘Everywoman.’ She has a very particular background, and even though the actresses playing her are somewhat different, they have a similar physical type, coloring and gestalt.”

As for their vocal quality, Letts said Steppenwolf had received a grant for an extra week of rehearsal and used it to bring in a vocal coach form New York, Gigi Buffington, to make sure they had the Ohio Valley sound down.

“Mary Page Marlowe was a college girl in 1960’s Ohio, and I didn’t want the modern sound of ‘up-speech’ or ‘vocal fry’.”

Although Shapiro originally planned to take a year off from directing while she got acclimated to her new role as artistic director, she ultimately couldn’t resist “Mary Page Marlowe,” and Letts was delighted by her decision.

“I have not encountered a better director of psychological realism than Anna,” said Letts. “Her notes to the actors are so insightful  — not about technical things like ‘louder’ or ‘faster,’ though that comes later, too. She really gets to heart of the matter and asks: ‘This is what I hear you saying, and is that what you intended?’ Ed Sobel, our dramaturg, does the same thing.”

‘The audience will be such a key component in this play,” said Letts. “It will be filling in a lot of the blanks, and it will be fascinating to see how that turns out.”

Blair Brown and Alan Wilder in rehearsal at Steppenwolf Theatre for the world premiere of Tracy Letts' "Mary Page Marlowe." (Photo: Courtesy of Steppenwolf Theatre)

Blair Brown and Alan Wilder in rehearsal at Steppenwolf Theatre for the world premiere of Tracy Letts’ “Mary Page Marlowe.” (Photo: Joel Moorman)