The trouble with interviewing actors on the job, as it were, is that you’re never quite sure who you’re talking to. Have we interrupted Alec Willows and Jon Bryden during rehearsals for Ages of the Moon, or is it Byron and Ames, the crusty old guys at the heart of Sam Shepard’s play, who are bemoaning the facts of the senior’s life via speakerphone?

“You find out that there’s things you didn’t take care of that never occurred to you that it might be necessary to take care of, so you end up with the same problems that you had when you were in your 20s. You realize you haven’t really solved anything. Especially if your life is devoid of love,” says the voice that identifies itself as Willows.

“It’s like waking up in the morning, and you look in the mirror and you don’t recognize the person staring back. Then you start to assess where your past life has gone to, and whether or not there’s enough milk in the fridge for Cheerios,” Bryden answers back.

The banter goes on, making a couple of seemingly contradictory things clear: these two veterans are perfectly cast in this production, and director John Cooper will have his hands full bringing Ages of the Moon to the Presentation House Theatre stage. With two weeks to go before opening night, Cooper can’t fully explain what he wants viewers to get out of the play, marked as it is by Shepard’s characteristic blend of psychological insight and half-articulated emotions.

“Right now, in trying to think what I would possibly say to you about a play that has such a rich fabric, there’s lots of different lines that go through it,” he says, on the line from the theatre. “There’s this whole existential thing, which I see in Buddhist terms of dealing with the groundlessness of life—and in another way, it’s two guys not looking at their own shit, right? So there’s all these different things, and it depends what day of rehearsal somebody asks me what thing is really interesting me.

“There is a great story there, from resistance to surrender—which is not fighting the truth anymore, the scary truth, and just slowly coming to terms with it,” Cooper continues. “To me, there’s great meaning in that. There’s also a poetic rhythm to it that happens from running into walls and letting go, and running into walls and letting go, and running into walls… So there is a kind of ebb and flow to it. Things keep shifting and shifting.”

What’s fixed is that Byron and Ames have wedged themselves into some kind of bolt hole—a fishing cabin, maybe, or some other rustic hideout—where they’re faced with the slow and remorseless unravelling of their lives. The wreckage of their wrong choices—the women disappointed, the money squandered, the vitality taken for granted—whirls around them as they seek solidity in their 50-year friendship. Which is all that remains for them, and yet not quite what it seems—much like the two central characters themselves, archetypical American males who also somehow represent the whole of the human condition.

“It’s really about the nature of being in your 60s, and facing existential questions and change and death and all these sorts of things,” says Cooper. “We do all this comic stuff to resist it—you know, behave foolishly and stuff—until we’ve suffered enough and have to stop fighting. It’s human-being stuff. That’s how I feel about it, anyway. It’s real stuff that people I know go through, more than ‘Here we are at the theatre, darling.’

“It certainly is a play,” he adds, “that’s more about inviting questions than offering simple answers.”

Ages of the Moon runs at Presentation House Theatre from next Thursday (October 27) to November 6.