Hell contains nine distinct circles, as anyone who's ever read The Divine Comedy knows. In the knockout new play 9 Circles by Bill Cain, we watch as a young American soldier recently discharged from the military metaphorically passes through each and every one of those circles. This is not a play about war. It's not a play about war crimes. It's a play about the human soul. The Marin Theatre Company's haunting, transcendent and almost unbearably intense production of 9 Circles, though hardly flawless, stands as one of the best and boldest new plays of the year.

Running through Nov. 7 in MTC's intimate Lieberman Theatre, 9 Circles, directed with taught focus of purpose by Kent Nicholson, follows the descent of Pvt. Daniel Reeves (an explosive and terrifying Craig Marker), beginning with his own personal first circle of hell as he is discharged from the service. A deeply troubled young man with a history of violence and personality disorder, the wise-cracking Reeves is infuriated by his "honorable discharge" ("Sounds like what your biology teacher says instead of saying 'cum,'" he snarls), wanting nothing more than to remain in Iraq, where he has seen his share of hell already.

Back in the States, Reeves is arrested, and gradually comes to understand the severity of his situation. He has been charged with leading a troop of soldiers on an unauthorized killing spree while serving in Iraq, an episode that included the rape and murder of a 14-year-old girl. Reeves claims he is being set up as a scapegoat, arguing his position to a series of visiting lawyers, ministers and psychiatrists, all played by the remarkable James Carpenter and a slightly less impressive (though largely capable) Jennifer Erdmann. Each new scene is announced as another circle, counting up to nine as the tightly mounting tension builds to an inevitable conclusion.

Through it all, Marker—whose astonishing, full-bodied fierceness may cause the audience to feel physically threatened at times—shows us Reeves' unraveling psyche. Trained to kill, recruited because of his willingness to kill, Reeves is torn between feelings of betrayal, rage, ironic disbelief, distrust and, a little too late, remorse. As he says after his arrest in Texas, "Everything we did over there is a crime over here."

Playwright Cain, whose impish Equivocation turned him into an overnight sensation last year, was awarded the Marin Theater Company's Sky Cooper new American play prize for the 9 Circles script. A practicing Jesuit priest with an extensive background in theater (he ran his own Shakespeare company for several years), Cain has been called one of the more remarkable and eloquent writers on the current American theater scene. 9 Circles proves why.

The script feels as if it could use some tightening, especially the final speech, in which Cain finds a surprising but appropriately effective way to describe the ninth circle of hell. But Cain is not afraid to ask questions that have no answers, and though his writing in this world premiere occasionally strays into preachiness, it's some of the best-written preachiness you're likely to see onstage this year.

'9 Circles' runs Tuesday–Sunday through Nov. 7 in the Lieberman Theatre at Marin Theatre Company. Showtimes vary. 397 Miller Avenue, Mill Valley. $32–$53. 415.388.5208.

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