On this afternoon, it almost feels as if the O’Neills are once again living in the Monte Cristo Cottage.

This New London house is where playwright Eugene O’Neill spent his boyhood summers — and where he lived his family drama. It’s where he set his autobiographical masterpiece, “A Long Day’s Journey into Night.”

And it’s where Flock Theatre is rehearsing for its production of “Long Day’s Journey.”

This is the scene:

Mary (portrayed by Anne Flammang), the mother of the Tyrone family that is the stand-in for the O’Neills in the play, is struggling with her morphine addiction. She gazes dreamily out the front window toward the Thames River, speaking of the fog as if explaining how morphine makes her feel: “It hides you from the world and the world from you. You feel that everything has changed, and nothing is what it seemed to be. No one can find or touch you any more.”

She fairly ignores the Irish maid (Amy Bentley) who gaily gabs on about an overly friendly male driver.

Mary eventually realizes the morphine she’s taken isn’t quite enough. Just as she is about to float upstairs for another dose, her husband (Christie Williams) and son (Victor Chiburis) return home, rattling their way in the front door. Trapped, she doubles back to the sitting room.

The father stops cold. He stares at his wife, suspicion etched on his face. He senses it. She has delved into the morphine again.

This is the first full-fledged production of “Long Day’s Journey” to be staged inside the Monte Cristo Cottage, and the actors, speaking in a pre-rehearsal interview, seem to deeply appreciate the authenticity of it all.

“It’s sort of an actor’s dream. It’s hyper real,” says Chiburis, who portrays Edmund, the character Eugene O’Neill based on himself. “You’re in the place that it actually takes place instead of a set, trying to recreate things … This is 100 percent real.”

And it’s not just the location that has an impact on the performers. Flammang says there are metaphorical ghosts here.

“I feel it mostly on the stairs. These are the steps the O’Neill family walked up, this is where Eugene O’Neill played as a boy … At times, if you just let it soak into you, it’s overwhelming. If those ghosts come in, it can’t but impact (you and your performance),” she says.

This production has been a long time coming for the New London-based Flock Theatre. Flock Artistic Director Derron Wood had contemplated the idea for years, and when the Eugene O’Neill Theater Center, which owns the Monte Cristo Cottage, gave the okay a couple of years ago for Flock to use the site, he was ready to go. But then a Broadway production happened. The fact that “Long Day’s Journey” was scheduled to play the Great White Way in 2016 (starring Jessica Lange and Gabriel Byrne) meant that the rights weren’t available to Flock.

Now, though, they are, and the cast has been rehearsing since September to gear up for the show. Earlier this month, they had the opportunity to begin working in the cottage itself.

Eric Michaelian, the actor playing dissolute, drunken brother Jamie, says that rehearsing in the Monte Cristo has utterly changed how cast members approach the characters and the scenes. It has helped them understand how close these characters are in this cramped house and how they can sometimes feel cornered.

They also have gotten a sense of how near the actors will be to the audience. The room where the play takes place is just 14-by-14 feet, and 25 chairs will be lined up on one side of it for theatergoers; they’ll face a table and surrounding chairs and will be able look beyond, seeing the staircase in the entryway and the portraits over the front-room fireplace of Eugene’s parents, James and Ella O’Neill.

“The audience will feel as if they’re watching a family, like they’re Peeping Toms, basically,” Flammang says. “I think that ups the stakes for us as actors … You have to commit to trying to be honest in every single moment because the audience will see anything that’s false.”

Indeed, it’s all such a confined space that the actors can be much more subtle in their performances. Michaelian notes that Wood, who is directing the piece, has said this is akin to film acting, where eye shifts and looks — things that might be lost in a big theater — can be powerfully effective.

Flock has a history of staging site-specific work, drawing focus “to these incredible historic properties and houses that are in this area,” as Wood says.

Indeed, the production makes full, rich use of the Monte Cristo Cottage itself. The performers enter and exit through the front door. They tromp up the staircase. When Mary hides herself upstairs, Flammang might pace the floorboards on the second floor. When maid Cathleen yells for the men to come in from trimming the hedges, Bentley will step onto the actual porch and call for them.

It’s not just the cottage that gives the tale its local connection. The play bubbles with New London references, Wood notes, including to the Thames Club, where the tiles of members’ silhouettes feature James O’Neill’s, and including fictional versions of a number of major figures in town, including the wealthy Harknesses.

Dividing ‘Day’

For two performances, Flock is breaking up “Long Day’s Journey” so that each scene is staged at the time of day the script specifies. So on April 22 and 29, the show will be presented this way: Act I at 9 a.m., Act II at 12:45 p.m., Act III at 7 p.m., and Act IV at 8 p.m. The show’s total running time should be a little over three hours.

The April 22 performance sold out quickly, prompting Flock to add an April 29 show with that timetable. That April 22 show was particularly popular with members of the Eugene O’Neill Society who are coming from as far away as Tennessee to see O’Neill’s greatest work done in the location it was set, at the time of day the script dictates. (The society is a scholarly organization that aims to promote and study O’Neill’s life and works.)

The other performances will feature the first two acts starting at 3 p.m., followed by a break, and then the third and fourth acts at 7:30 p.m.

There are theatrical reasons for the unusual schedule. Wood says the idea is to play with the extension of time, space, place and sound. Sound, for instance, travels differently at various hours. And audience members will get to see how light wanes over the course of “Long Day’s Journey,” reflecting the loneliness that creeps in as the Tyrones’ day goes on.

The breaks between scenes, Wood figures, will also be “helpful for an audience to really understand this ‘Long Day’s Journey into Night.’ And it is — it’s a long day, and the play itself is a very long production. Those multiple breaks, I think, will help (audience members) digest what those characters are going through when they’re not in that house and in the scene.”

Those breaks will also allow audience members time to, say, go to the local cemetery where all the O’Neills except Eugene are buried (more on that later) or, with special arrangements on Saturdays, they can dine at the Thames Club in New London, as James O’Neill did, Wood notes.

The past echoes the present

Certain elements of the “Long Day’s Journey” story are clearly still timely. Mary Tyrone is a victim of morphine addiction, which serves as a driving force in the play. That struggle is echoed in the current opioid epidemic.

That isn’t the only element that has modern-day parallels.

“You have an immigrated family from Ireland that’s still under a lot of pressure against immigrants and Catholics in that time period. You have a father who can easily, say, create his own facts and beliefs about the world to push forward cheap health care for his son,” Wood says. “There’s a lot that I see that just keeps coming up again and again. It’s really interesting listening to the text, and then coming home and looking at (news) on Facebook and saying, ‘Oh, that’s kind of interesting.’”

He notes, too, how the Tyrone father is quite religious and battles atheist son Edmund, setting up faith-versus-science friction.

Wood describes the Tyrones as the quintessential American dysfunctional family.

“It’s a family that just doesn’t listen to each other, really can’t hear the pain and what is going on (with other family members) and is constantly blaming each other,” he says.

Wood notes that, in the end, Eugene O’Neill didn’t want to be buried with his parents and brother. The whole family is buried in St. Mary’s Cemetery in New London, except for Eugene, who is interred in Boston.

“Long Day’s Journey” is certainly a challenging play for actors.

“It’s like training for a long athletic event,” says Christie Williams, who portrays Eugene’s father, James, who centered his acting career on starring in “The Count of Monte Cristo.” “The play is so huge, and all of the roles are monster roles. So we literally have to build up physical and intellectual strength.”

The bottom line just might be this: Williams notes, “This play is a privilege to be in. It is a masterpiece. And to do it here, it’s a very great privilege.”

If you go

What: Flock Theatre production of “Long Day’s Journey into Night”

Where: Monte Cristo Cottage, 325 Pequot Ave., New London

Special “Long Day” performances: April 22 and 29; Act I at 9 a.m., Act II at 12:45 p.m., Act III at 7 p.m., and Act IV at 8 p.m.; tickets $45

Other performances: Remaining Saturdays and Sundays in April; first half of the play starts at 3 p.m., second half at 7:30 p.m.; tickets $35

Already sold out: Shows on April 15 and 22

Reservations required: (860) 443-3119 or email flocktheatre@hotmail.com