“What are you trying to get at?” a man on the phone demands. “What is your goal?” 

He’s speaking to — berating, really — reporter Tyler McBrien of the Atlanta Journal-Constitution. McBrien’s response is as gentle as his subject is combative. “Like I said, it’s just to get to the bottom of who blew up the Guidestones.” 

This fascinating, frustrating exchange happens late in McBrien’s seven-part series, “Who Blew Up the Guidestones?” By this point, listeners will be familiar with the question, as McBrien repeats it dozens of times while talking to law enforcement or swapping theories with locals. Sometimes he invokes it as a rhetorical aside, a naked plea for the truth to appear.

In a sense, the podcast’s premise is extremely simple. On July 6, 2022, in Elberton, Georgia, someone destroyed a massive stone monument that had been standing since 1980. Occasionally dubbed “America’s Stonehenge,” the monument was made of great granite slabs covered in mostly hand-tooled writing translated into eight languages. Over the Guidestones’ relatively short lifespan, they attracted devoted visitors, often of the gothy, witchy variety, as well as vocal opponents, often of the Bible-thumping variety. 

Then, one day, there was an explosion — and the Guidestones were gone. 

The ensuing investigation by law enforcement is best described as unhurried. McBrien postulates that perhaps this was because the incident resulted in no actual casualties. The lack of interest from the police and a lack of suspects left room for conspiracy theories to flourish. But it also allowed McBrien and company to investigate the matter mostly undisturbed, conceivably positioned to uncover not just the who, but also the why.

Bucking the “I dunno” doctrine

Longtime fans of narrative true crime are no strangers to uncertainty. The floridly inconclusive end of the first season of “Serial” helped set this precedent, mostly out of necessity. Host Sarah Koenig and her team never did get to the bottom of whether Adnan Syed murdered his girlfriend. And yet, they had a series to resolve. 

Koenig, to her credit, shared much of her hand-wringing on-mic, voicing concerns that she had let the audience down with a non-ending. Her musings, though, spawned a popular podcast template. Call it the “I dunno” doctrine. “We may never know who the killer is,” the doctrine teases, “But aren’t you glad we explored it together?” It’s a framework that constantly reminds listeners that the journey is the destination. To expect more is considered small-minded, even gauche. 

The “I dunno” doctrine has become so pervasive in podcasting that it can be genuinely surprising when a series shows up with receipts. In that sense, “Who Blew Up The Guidestones?” has welcome surprises at every turn. McBrien and his producing team — which includes staffers from the AJC and Goat Rodeo — dig in, gumshoe-style, to find clues missed by both Elbert County law enforcement and the resplendently lackadaisical Georgia Bureau of Investigation.

In fact, much of the drama in “Guidestones” comes down to whether anyone with more authority will stop McBrien et al. from asking questions. It seems inevitable that someone will shut this whole thing down, and yet the reporters keep landing on hard evidence that gets closer and closer to provable truth.

In episode five, “Jesus, Guns, and Babies,” McBrien says that investigations “are about shrinking the known universe.” “When we started, we were looking for anyone in the world with a motive against the Guidestones.” After months of digging, the team manages to focus its spotlight with increasing precision. Suffice to say, the search yields, if not perfectly definitive results, a conclusion reminiscent of David Fincher’s “Zodiac” in both tone and substance. Certain mysteries, for legal reasons, can’t be declared solved, but listeners still leave feeling like they know what’s up.