“Monolith” is an exercise in the simple power of storytelling, compelling voices summoning up all the acting gravitas they can to evoke chills and a fear of a vague, unknown “something.”

Built around a dogged podcaster, her recording studio and her phone, it is the picture of minimalism, a primer on no-budget movie-making and a reminder of what people with imagination were forced to strip down to making movies during COVID lockdowns.

But one can appreciate all that is accomplished with the bare minimum of visual variety and external clues, threats or assistance and still find this thiller wanting. At the end of the day, you’ve got to deliver some payoff worthy of the paranoia and suspense everybody is talking themselves into.

Lily Sullivan plays our interviewer, whom we meet, mid-call, on her “Beyond Believable” podcast. She’s pandering to an audience of the conspiracy-minded, trying to modulate the crazy, and doing it from a position of weakness.

She needs their attention, and as a recently-disgraced journalist whose career took a huge hit when she published what she believed to be true, not what she could verify, she can’t talk down to anybody and be taken seriously.

An anonymous email tip mentions somebody who got something once in her corner of Australia — a “brick.” And from that unpromising tease, she plunges into days of calls, interviews, “verifications” and stories told by a housekeeper, an art dealer, scientists and others as she tries to ascertain who got such “bricks,” what they looked and felt like, what their arrival portends, what the “writing” on them means and how they changed the people who received them.

“It felt like something of someone was trying to talk to me,” assorted nervous interview subjects declare.

And as out interviewer plunges deeper into this “unsolved mystery,” fretting over “something awful is coming” and “the dark forces behind this,” the viewer is allowed to recall her assertion “I’ve just got to make a story that will make people listen.”

The seriousness of the calls, sometimes treated in overlapping audio montages as this “story” “blows up,” the creeping way director Matt Vesely has the camera prowl her parents’ remote and empty — save for a pet turtle named Ian — house, makes us consider what might be coming, if someone on the phone is having her on or if what might be happening is all in this woman’s head.

But there are limits to how much of a chill we can get from implied-not-overt threats, and there’s risk in when you actually get to a put-up-or-shut-up point and a “Monolith” must be produced, that it won’t all have been worth it.

And that’s when this slow-simmer/not-really-building thriller sputters, having exhausted most of the tricks in the “scare you without showing you” filmmaking arsenal.

Not bad, as far as it goes. But not all that, either.

Rating: R, profanity, suggestions of violence

Cast: Lily Sullivan, with the voices of Linn Coper Tang, Matt Crook, Ansuya Nathan and Terence Crawford.

Credits: Directed by Matt Vesely, scripted by Lucy Campbell. A Well Go USA release.

Running time: 1:34