Memories are ephemeral, and they are malleable. And memories are helpful ... or is it harmful?

All of the above may be true, and yet we trust our memories as stepping stones for whatever the next step may be.

In the not too distant future of “Marjorie Prime,” what we know of memory, and its mysterious way of disappearing over time, really hasn’t changed. It’s the means we use to confront memory loss that has taken an eerie leap.

In the haunting, absorbing world of Jordan Harrison’s play, 85-year-old Marjorie’s memory is fading. To help her fill in the blanks, her daughter, Tess, and husband, Jon have acquired a Prime — a hologram made up of  “a gazillion pixels” and made to look like her late husband at age 30something.

The production at Pittsburgh Public Theater is striking in its subtle chills. It begins with the pristine, perfectly appointed home of Jon and Tess, whose mother Marjorie lives with them. A recent addition to the household is the artificial intelligence Walter Prime, a companionable memory jolt for Marjorie.

The idea is to feed the Walter remembrances of Marjorie’s life, and let the Prime be the reminder of things past, before they fade from her consciousness.

Ah, but what are the facts of her life? Have they been manipulated, enhanced or completely changed?

Tess and Jon debate the presence of Walter as you might expect — it’s natural that Tess is creeped out by this presence of her father as a young man.

Jon (Nathan Hinton) embodies a devoted, patient husband and son-in-law. He is seemingly all for the Prime, but he wonders aloud, “How much does she have to forget before she’s not your mom anymore?” Daina Michelle Griffith, as chatty, troubled Tess, is even more skeptical, and worried about a family secret. She believes that some memories are best left behind.

Tess’ biting humor reflects that of her mother, Marjorie — Jill Tanner, who moves with old age but whose mind seems whip-sharp, with references to pop culture and music sometimes readily available. But then there are the moments of her life that remain on the tip of her tongue, forgotten or repressed.

As Walter Prime, Ben Blazer exudes a Clark Kent-meets-Ward Cleaver sort of guileless charm. He seems more robot than hologram as he sits off to the side when not summoned, but his repeated movements and practiced speech mark him as something other than human.

When engaged, his Walter is programmed to be curious, or at least ask lots of questions. His conversations with Marjorie are something akin to playful, and in that, he is a relief to Marjorie from the constant worrying of her daughter — a case of the child becoming the parent.

The consequences of a Prime’s presence in a family’s daily lives plays out on set that seems futuristic in its shades of beige and simple, functional lines. Intermittent projections clue us in to the technological advances we are witnessing.

Marya Sea Kaminski, in this finale of her first season as artistic director of the Public, directs a haunting and provocative work with a sure and subtle hand.

Much as the Netflix series “Black Mirror” taps into our dependence on and uneasy relationship with technology, “Marjorie Prime” presents a view of the future that won’t be forgotten anytime soon. The play comes to an indelible and chilling conclusion that you may be debating and mulling over for days and weeks to come.

Pittsburgh CLO’s ‘Grease’

Let’s start by saying Clay Aiken in a pink-sequined suit is everything fun and fanciful about “Grease,” and his voice takes “Beauty School Dropout” to glorious heights.

It’s a world where Clay Aiken can play the same role — Teen Angel — also portrayed by Billy Porter on Broadway and Frankie Avalon on film, and Aiken plays it to the hilt, even getting a lift from a shirtless trio of chorus men.

Now that I’ve fanned myself, this Pittsburgh CLO “Grease” is a hybrid of the Broadway play and the movie — it uses the music created just for the film, opening with the title song and including “You’re the One That I Want” and “Hopelessly Devoted to You.”

There is a little less raunch than the original Broadway version, with lyrics to songs such as “Greased Lightning” cleaned up as in high school versions. But in case you are a parent who worries about such things, it should also be noted that there is an, um, mooning from the stage.

“Grease” is still a ’50s-era story of boys who love cars and pressure girls for sex, a possible teen pregnancy and those high school friendships you never forget.

The CLO production has some terrific voices — Jackie Burns as Rizzo, Zach Adkins as Danny, Kristen Marten as Sandy and Damon J. Gillespie as Doody among them — and it really moves.

The opening to “Grease,” with the principals emerging from lockers, is a cute idea, and the ensemble dance numbers come in waves of nostalgic moves, with some modern touches mixed in, courtesy of director/choreographer Barry Ivan.

This CLO production isn’t just a blast from the past; it’s also a fun night for Pittsburgh musical theater fans to see local actors such as Melessie Clark, Mei Lu Barnum, Andrea Weinzierl and Michael Greer get front-and-center moments.

The energy level is high, but there’s no question it steps up a notch when Clay Aiken struts out in the second act and gives Pittsburgh a taste of why his Claymates are hopelessly devoted to the former American Idol.

Sharon Eberson: seberson@post-gazette.com or 412-263-1960. Twitter: @SEberson_pg. Sign up for the PG performing arts newsletter Behind the Curtain at Newsletter Preferences.

First Published: June 10, 2019, 4:34 p.m.