If theater is meant to spark conversation, its mission is accomplished with Penguin Rep’s latest production, Joel Drake Johnson’s “The Fall to Earth.”

The play’s final moment — which Johnson has said was meant to be “deliberately ambiguous” — certainly had people talking after Sunday’s matinee.

“What does it mean?” one woman wondered aloud.

“Do you think…?” one wife asked her husband, who offered a long “Nooooo” in reply.

In the parking lot, one theatergoer turned to the members of her party and said, “We’re going to have to have a long talk about this one.”

You won’t learn about the ending here — no “spoiler alerts” required — but rest assured that, after 95 minutes, it comes as a surprise.

Johnson’s one-act play — on stage at Penguin Rep in Stony Point through July 20 — involves Fay and her daughter, Rachel, who check into “a typical chain motel in a small American town.”

Fay chats nervously and constantly; Rachel offers only the most minimal answers.

Fay dangles her legs off the side of the huge bed, flexing her feet absentmindedly as if pressing on the gas with her right and the brake with her left.

But that kind of control eludes Fay. This trip is not about control.

They’ve come to this place because there has been a death and there are details to see to.

As she has no control over the circumstances, Fay is determined to learn every detail she can about the death. Knowledge, they say, is power and the powerless Fay will take anything she can hold on to at this point.

Rachel wants to take care of everything. It’s not that she’s trying to spare her mother, necessarily; she just wants it to be over, to tie up all the loose ends and get on with her life.

The play’s third character, police officer Terry Reed, takes her job seriously if a bit too personally. She is clinical to start, laying out the elements of the case.

Each fact is a dagger in Fay’s heart, but she’s determined to survive each one. Give me more, she seems to be saying, as she plasters on a tight smile to mask the pain.

Terry can’t help but empathize and, before long, she’s overstepped the boundaries of her job.By the end, mother and daughter — who both declare “I can take it” — are left damaged but determined, haunted but whole.

Director Joe Brancato has taken a risk here, programming a serious work in midsummer, when lighter fare dominates local stages.

But it’s a calculated risk. With a stellar cast and Penguin’s customary attention to detail, Brancato has fully rendered Johnson’s thought-provoking work.

Michele Pawk, a 2003 Tony-winner as an alcoholic mother in “Hollywood Arms,” completely realizes Fay’s complicated nature in a performance that demonstrates nuance, control and split-second timing.

At times, Pawk plays Fay as a sort of Central Casting mother with a guilt-edge guarantee: If Rachel has a cell phone and can call anyone at anytime, why doesn’t she call her mother?

Pawk’s Fay is also coy and playful, sashaying blithely in her new surroundings.

Turning on a dime, Fay is fierce, barking out demands.

Then she’s vulnerable, giving herself a pep talk: “Don’t let yourself get down. Don’t let yourself get down,” she repeats. “Look strong,” she says.

When she comes unglued — which we know is bound to happen — it’s heart-rending. All control is lost.

As Rachel, Laura Heisler has an unenviable task: Playing opposite Pawk’s raw vortex of vulnerability, Heisler has to listen to every word but appear not to care too much. After all, her character is here to get it over with.

The young actress, seen in Broadway’s “Coram Boy” last year, is natural and unaffected — all in control — until the final moments when a revelation gives us a glimpse of the life Rachel has lived. Heisler’s performance is something to see, an exercise in observation.

Amelia Campbell, a 1991 Tony-nominee for “Our Country’s Good,” plays Terry with sweetness, compassion and a touch of naiveté. As she sees the impact her words have on Fay, she tries to undo the damage.

Joe Egan’s set is efficient and appropriately spare, converting seamlessly — in a rapid set change — from an Anywhere, U.S.A. motel room into an office in at an Anywhere, U.S.A. police station. In what seems like too short a shortcut, Egan chose to re-use the desk, chair and dresser from the motel room as the furniture in the police station, which seems odd, unless this police station is decidedly high-end, which is not the case here.

Joanne M. Haas’ costumes are appropriate — Pawk in a powder blue business suit (that her character tugs at), Heisler in jeans and Campbell in full police uniform.Gary Marder’s lighting focuses our attention where it needs to be and dims effectively to that final tableau that will have folks talking.

‘The Fall to Earth’

Where: Penguin Rep, 7 Crickettown Road, Stony Point.

When: Through July 20. 8 p.m. Thursday, Friday and Saturday, with matinees at 4 p.m. Saturday and 2 p.m. Sunday.

Tickets: Individual tickets are $32, and $16 for those 30 and younger. Discounts are available for groups of 10 or more.

Call: 845-786-2873.

Web: www.penguinrep.org.

Photo by Andrew M. Horn: The cast of “The Fall to Earth” is, from left: Amelia Campbell, Michele Pawk and Laura Heisler.