At the beginning of Dan O'Brien's play, two actors introduce themselves as Paul Watson. One then speaks as Terry Gross, the familiar voice of NPR's Fresh Air. Soon after, the other also adopts the radio host's serene voice. A few lines later, the conversation draws in the playwright. Suddenly, it's a rapid-fire exchange between three characters performed by only two men. Confounding yet not confusing, it's a fitting opening to this intricate production.

Watson—the man doubly introduced in the play's first lines—is a war journalist who won the 1994 Pulitzer Prize for a photo of an American soldier being dragged through the streets of Mogadishu. The image haunted Watson. He claims that as he snapped the shutter, the soldier spoke to him: "If you do this, I will own you forever." O'Brien, the playwright, heard Watson interviewed on NPR in 2007 and sent him an email. The ensuing exchange led to The Body of an American, premiering at Portland Center Stage.

Body is an unconventional exploration of trauma, vulnerability and trust, set on a stark stage as photos and maps slide behind. Though each actor has a primary role—William Salyers is both hardened and wounded as Paul, and the superb Danny Wolohan plays Dan with energy, humor and sorrow—they also take on smaller roles, and occasionally speak as the opposite character. Director Bill Rauch deftly harnesses the play's fluidity, and it's a treat to watch these skilled actors flit in and out of roles, altering their gaits and voices with ease.

The email exchange makes up much of the first act: Paul recounts terrifying stories from war zones, Dan diminishes his own suffering in relation to Paul's, and each accuses the other of half-truths. Dan to Paul: "Everything has this kind of Hemingway patina to it." Paul to Dan: "You only speak in these mock-whimsical, ironic asides." O'Brien's language is vivid and grisly—a baby's head is "cracked open like a coconut."

In the second act, the men meet in the Canadian Arctic, the contours of the icy mountains carved with light on the backdrop. Though this too-long act loses some of the early urgency, it's a fascinating study of how these two men learn to relate. Body begins with matters of global significance but personal questions—about healing, forgiveness and human connection—most resonate.

SEE IT: The Body of an American plays at the Gerding Theater, 128 NW 11th Ave., 445-3700. 7:30 pm Tuesdays-Sundays, 2 pm Saturday-Sundays, noon Thursdays. Through Nov. 11. $25-$54.