Agnes (Jackie Davis), left, and R.C. (Marie Michaelle Saintil) chat in a Oklahoma City motel room in the Providence Black Repertory production of Bug.

Providence Black Repertory / Jori Ketten

One of the neat things about Bug, the latest offering from Providence Black Rep, is that it’s so ambiguous. Is Peter, the AWOL soldier, really the target of a government conspiracy? Is he being attacked by mind-controlling bugs? Or are he and Agnes, his waitress lover, delusional paranoids?

We never really know, even as this chilling play winds toward its gripping conclusion. But it sure is a lot of fun trying to figure it out.

Bug, written by Pulitzer Prize-winner Tracy Letts, author of the Broadway hit August: Osage County, is one of those plays that keeps you guessing, a thriller that pulls you deeper and deeper into a web of intrigue and suspense. And at Black Rep the cast and crew are doing a bang up job, giving a performance that keeps you on the edge of your seat, at least in the tense second act, when things really start to pop.

What begins as a possible infestation of bed bugs turns into a plot befitting an episode of The X Files.

The play, which was made into a movie starring Ashley Judd, is set in a seedy Oklahoma motel room where 27-year-old Peter is living with Agnes, a lonely divorcée in her mid-40s. Letts’ script suggests a white world, a place populated by red necks, ex-cons and poverty-stricken Okies. But director Megan Sandberg-Zakian has cast the play with mostly black actors from the company’s affiliate artist roster, and that gives this tale of people living on the edge a special potency.

It’s not hard to believe that people of color might be governmental guinea pigs. Or that lives so marginalized might end up dealing with psychological problems.

Anyway, Sandberg-Zakian has given us a Bug that builds slowly, in one soaring crescendo of fear and uncertainty. When we first meet Agnes, she is a strong self-assured type with a fondness for the crack pipe. Peter, who is homeless, shows up with a friend of Agnes’ and spends the night, sleeping on the floor. The two bond almost immediately, as Peter begins to share his fears about being watched.

But rather than reason with him, Agnes, played by an increasingly agitated Jackie Davis, buys into Peter’s belief that the government has implanted an insect egg sac in his tooth and that he is being controlled by microscopic beings. In a fairly implausible twist, Agnes loses all sense of objectivity and becomes as paranoid as Peter.

But then Bug is in part a love story, a tale on one level about romantic entanglements and the way they affect us.

The other interesting transformation comes from Cedric Lilly’s Peter, a nervous, geeky guy who doesn’t fit in. At first Lilly’s goof-ball schtick seems a little forced, a little awkward. But as he becomes consumed with his obsession about bugs, he becomes this dramatic force, a crazed character who dominates the stage.

Hip-hop artist Raidge plays Agnes’ ex, Jerry Goss, with simmering discontent, a man whose anger can spill over at any moment. Jerry has just been released from prison after serving a sentence for armed robbery and now he is back in Agnes’ life, looking for a place to stay and some spending money. He just might be the breather who keeps calling her on the phone. And in some ways he’s the sanest of the lot.

Marie Michaelle Saintil is Agnes’ skeptical gay friend RC, and Bob Jaffe is terrific as spooky Dr. Sweet, the psychiatrist who shows up to bring Peter back to the hospital where he was confined for years.

Jaffe plays the role in a campy, highly stylized fashion, with shifty eyes, and deliberate gestures. But it works, making him seem all the more quirky, mysterious, and a little comic.

This show is not for the squeamish, though. There is plenty of blood and gore, thanks to the makeup magic of Michael Dates, a recent Los Angeles transplant who also does hairstyling. At one point, Lilly lifts up his shirt and reveals a body covered with oozing sores, presumably the result of his run-in with bugs.

There is also a gruesome scene where Lilly pulls a tooth with a pair of pliers. And there is a bloody knifing at another point.

It is for this reason and some salty language that Bug is recommended for mature audiences.

Other realistic touches include the sound of cars whizzing by the open door of the motel room and the chugging of a helicopter heard overhead, as though the place were under surveillance. And that only adds to the sense of dread.

Bug runs through Oct. 19 at Providence Black Repertory Company, 276 Westminster St., Providence. Tickets are $20, $10 for students and seniors. Call (401) 621-6123 or log on to www.arttixri.com.

cgray@projo.com