Lamb (Brianna Letourneau) and Doc (Scott Ward Abernethy) in “The Magic Tree” at the Keegan Theatre. (C. Stanley Photography)

No doubt Northern Irish playwright and Belfast native Rosemary Jenkinson knows her political infighting, the loyalists and Protestants and paramilitary subgroups/crime rings that apparently are still jostling against one another. If you’re keeping score on that front, Jenkinson’s “The Dealer of Ballynafeigh” may strike you as corrosive satire.

Jenkinson’s cockeyed underworld features the usual sweetly violent suspects: a bumbling man named Billy and his nattering Ma, both mixed up in the sort of mob and drug hijinks in which farcical characters threaten each other with guns, knives and power tools.

“Dealer” is half of a two-play rep that the Keegan Theatre is offering for the Women’s Voices Theater Festival, and this shambling 80-minute show is the lesser selection. Ursula Rani Sarma’s moody “The Magic Tree,” about a young woman surviving a sexual assault in Dublin, overcomes a deeply uncertain first act as it eventually straddles hemispheres and evokes mass atrocities.

That “Magic Tree” first act will surely make you squirm, though. A woman, far too preciously named Lamb, breaks into an empty house one dark and stormy night. She’s followed inside by a shuffling lad named Gordy, who seems both shifty and innocent (a blend neatly played by Chris Stinson). The real bad guys — Gordy’s mates — are just outside. A rape is afoot.

Gordy (Chris Stinson) and Lamb (Brianna Letourneau) in “The Magic Tree.” (C. Stanley Photography)

How we are supposed to laugh at the jokey byplay between Lamb and Gordy is anyone’s guess, especially once the thuggish ringleader Doc (Scott Ward Abernethy) and his big, slow sidekick, Lenny (Ryan Tumulty), arrive. It’s sort of held together, though, by Brianna Letourneau’s cold focus as Lamb.

The intriguingly tranquil second act seems to be on the Southeast Asian beach Lamb had mentioned as Sarma’s script takes an intensely poetic turn, smartly complemented by co-directors Matthew J. Keenan and Colin Smith. Robbie Hayes’s wood-plank set is cleverly rearranged to form a giant tree, and local urchins begging Lamb and Gordy for cash are rendered as alien-voiced figures made of light.

Sarma’s brooding portrait — a U.S. premiere — draws a dark parallel. There’s Dublin, where dumb lads like Gordy can plan a rape and repeat stupidities like “All girls are like that” (a Gordy refrain), and then there are the mass graves of an Asian genocidal site. A quiet, disturbing power steals over this off-balance show; part two is as fascinating as part one is off-putting.

“Dealer,” though, is one-note, and it’s a sloppier performance (though both scripts involve crimes on rainy nights, with the prospect of victims being dumped in the sea). Abigail Isaac Fine’s loosely guided cast blunders through the hyperactive comic language Jenkinson gives her stock figures, and the slack speech and direction sabotage the enterprise. If this sort of dark caper is to have any chance, the execution (and the executions) must be crackerjack.

Instead it wobbles across turf trademarked by Martin McDonagh, whose savage humans-to-hamburger adventures continue to serve billions. (Scena Theatre’s “The Cripple of Inishmaan” starts this weekend at the Atlas Performing Arts Center, and Keegan has scheduled “The Lonesome West” for next summer.) Once you know Jenkinson has real Belfast targets in mind, you feel bad for not getting more out of it. On the other hand, with dimwit figures stuffing drugs down their rivals’ throats and bleeding all over the stage as a gang that can’t shoot straight, “Dealer” looks like a dark slapstick picture that’s been exported from Ireland many times before.

“The Magic Tree,” by Ursula Rani Sarma. Directed by Matthew J. Keenan and Colin Smith. About two hours. Lights, G. Ryan Smith; costumes, Kelly Peacock; sound, Tony Angelini; projections, Patrick Lord.

“The Dealer of Ballynafeigh,” by Rosemary Jenkinson. Directed by Abigail Isaac Fine. About 80 minutes. Scenic design, Robbie Hayes; lights, G. Ryan Smith; costumes, Kelly Peacock. Sound design, Dan Deiter. With Peter Finnegan, Michael Kozemchak, Jane Petkofsky, Bradley Foster Smith and John Stange. Through Nov. 13 (“Magic Tree”) and Nov. 14 (“Dealer”) at the Keegan Theatre, 1742 Church St. NW. Tickets $25-$36. Visit www.keegantheatre.com.