If you can’t smell a rat or two or ten during the first few minutes of Neil LaBute’s In a Forest, Dark and Deep, then your olfactory integrity must be seriously compromised.

Well-mannered, well-read, well-credentialed college dean Betty has summoned her foulmouthed, beer-swilling, literature-hating carpenter brother Bobby to a cabin she owns in the woods. The guy who’s been renting the place mysteriously disappeared a few days ago, she says, and she needs help boxing up the stuff he left behind. Betty has a perfectly good husband sitting idly back at home, she and Bobby rarely spend time together and can barely pass a civil moment in each other’s presence—yet she asks Bobby for help. Hmmm.

Bobby comes in out of an ominous thunderstorm and starts laying into Betty about all the guys she fucked around with when she was a teenager. Check. Betty casually remarks that, even if they can’t pack up all the books, the filing cabinet absolutely must go. Check. And when the ominous thunderstorm isn’t knocking out the power, the sibs spend a good two minutes remembering how dad always used to say the truth hurts. Check-checkity-check-check.

LaBute may be known for his pitiless vivisections of humanity’s darker side, but in this play, which premiered last year at London’s Vaudeville Theatre, he’s gone a bit Agatha Christie on us. The rat smell hardly lets up throughout this 90-minute, intermissionless evening. Even Joe Jahraus’s passionate, expertly paced American premiere for Profiles Theatre—a company with a long history of staging compelling LaBute productions—can’t find the depth the script keeps promising.

The perverse need to unearth dark domestic secrets—particularly the ones everyone already knows—has been a robust theme in American drama at least since Long Day’s Journey Into Night. And it’s hard to miss the debt In a Forest, Dark and Deep owes to Sam Shepard’s Fool for Love, especially when it comes to those odd, tin-eared moments that hint at Bobby’s more-than-brotherly desire for his sister. But turning the quest for familial truth into compelling drama requires sophisticated plotting. LaBute mostly just lays things out where you can’t help but trip over them.

To illustrate the tensions between Betty and Bobby, LaBute drops some unresolved adolescent resentments over here and a couple recent betrayals over there. Then he sets off some well-timed bombs designed to upset audience expectations. Betty is the respectable one until we discover that she can’t order a tuna sandwich without lying. Bobby is a shiftless lowlife until it turns out he’s bent on forcing his strict moral code on his “loose” sister. When round one of sibling rivalry is over, LaBute has Bobby and Betty dance to an old pop song so they can fall giddily into each other’s arms, demonstrating that, yes, they also love each other. Then they come out fighting again. It’s lazy and schematic.

Through it all, Bobby relentlessly demands “the truth” from Betty. Why did the missing renter keep a fancy framed photo of himself in the cabin? What’s the story behind that other photo, the one showing Betty with her arm around the renter’s shoulder? Why isn’t Betty’s husband helping her pack up the place? Does her hubby even know about the cabin? Again and again Betty admits something under pressure, then dodges Bobby’s questions about that admission until she’s backed into a corner, at which point she frees herself by slightly amending her story. Then the new version unravels.

In a Forest is essentially a reworking of LaBute’s 2007 play In a Dark, Dark House, which Jahraus directed to devastating effect in 2008. That script concerns two brothers—one an accomplished professional, the other a dead-end menial worker—trying to wrest traumatic adolescent secrets from each other, with huge implications for both of them. This time only Betty’s secrets matter. Bobby’s life will be pretty much unaffected whether she owns up or not. So his unceasing efforts to reveal those secrets is basically a theatrical device. Trouble is, LaBute has turned that device into the play’s main engine. The final revelation of Betty’s harrowing predicament would deliver a powerful emotional wallop if everything that precedes it didn’t feel so deliberately engineered to produce a powerful emotional wallop.

Thanks to intelligent, authoritative performances from Darrell Cox and Natasha Lowe, there’s plenty of interesting stuff to consider here: questions of how minor adolescent indiscretions can poison adult relationships, how the need to feel desirable can pollute self-worth, how lies can both heal and destroy, how sin can exist independent of religiosity. Still, had LaBute found a convincing way to dramatize these big ideas, they might’ve been more than interesting. They might’ve yielded truths.