For a playwright with a knack for cold, sinister concision, Canadian-born, London-based Robert William Sherwood has a remarkably easy laugh. Contemplating absurdity sets him to chortling as he describes a recent day job as a computer programmer for Arthur Anderson. " I was in the department that got them into trouble. I worked for their flagship, which is business consulting. " Sherwood isn’t expecting an indictment (though the Justice Department did make a special mention of the " London office " ). But he’ll soon endure another kind of scrutiny when his neo-noir suspense drama Absolution makes its Boston-area debut, courtesy of American Repertory Theatre New Stages, at the Hasty Pudding Theatre.

In Absolution, which is set in Vancouver, three high-school companions are involved in a horrific sex crime. Fifteen years later, there’s an unexpected reunion. One has become a successful insider trader; another is a failed professor of classics turned newspaper proofreader. The third has found the Lord and insists that the crime needs airing, if not punishing. Sherwood cites Mamet and Pinter as stylistic mentors, and the dialogue is indeed short and snappy, though the atmosphere of accusation and revelation is riven with ambiguity and growing rancor. Crucial relationships remain gauzy; others intensify as the trio come to terms with what happened. Or what didn’t happen. As ART artistic director Robert Brustein explains, " It isn’t the crime that’s at stake — it’s the consequences. "

Absolution was partly prompted by a notorious Canadian murder case, though Sherwood can’t recall the details. ( " How ironic, " he muses. " To write a play about language and memory and have forgotten. " ) A wild London party and a morning-after reverie provided more input. " An image came to me of two high-school kids waking up and something horrible having happened. Unfortunately it’s like a lot of plays that were done in the mid ’90s. It’s very sensationalistic but not that interesting as a dramatic device. " He put the idea aside and years later came up with the twist of " cycling 15 years ahead. Then I said, ‘Now that’s an interesting idea. Now you’ve got a play.’  "

The drama got raves in Los Angeles, at Steppenwolf Theatre in Chicago, and in London, where it was a Time Out Critic’s Choice twice. Although it received mixed reviews at the National Theatre of Israel, it ran there for 18 months. Much, it would appear, depends on the staging. Sherwood is clearly delighted to be in on the ART rehearsal process, where he can partake of discussions with the cast and director Scott Zigler that range from Mamet to grammar. Along the way, he’s " hoping this will be the definitive production of this play. "

A clean-shaven, six-foot-something fellow (he claims not to know his exact height), Sherwood has an open countenance that’s noticeably unblemished for someone who spent his adolescence playing national-level youth hockey in his native Vancouver. And how many left-wingers went on to academic careers in classical Greek and Latin? He stopped short of a PhD and in 1994 relocated to London, " with the specific goal of doing a career in theater. "

During his first year, he saw more than 150 plays. In his second year he wrote four of his own. The first was Nero, about the Roman emperor, but he quickly found a sardonic stride with B-Play (Broads, Bourbon, Bullets, and Betrayal). Getting produced was another story: " You quickly realize it’s a very closed shop. " He played down his Canadian background (he’s virtually accent-free) so that the locals could " make whatever assumptions they want. " Laughing again, he says, " I’ve traveled enough now that I’m not really sure where I come from . . . I don’t feel very Canadian when I’m there. I’m not entirely British, either. I’m not American, though I constantly write about Americans. "

Four of Sherwood’s plays have premiered at the White Bear Theatre, which is part of the London " Fringe " scene, where " everything is done on the cheap and underwritten by the British government on dole checks. " Since then, he’s specialized in psychological drama (The Last True Believer, about the aftermath of the Berlin Wall, is currently at Seattle Rep). Yet his biggest influences remain the hard-boiled philosophers of past millennia. " Latin gave me the words for everything, " he says with unexpected solemnity. " It actually allowed me to write very complex stuff. Cicero was a huge influence. I studied him for years. " With another rich chuckle he offers a comment any noir author of the Golden Age would appreciate: " It’s all about manipulation. Which is what art is. "

Absolution is presented by American Repertory Theatre New Stages at the Hasty Pudding Theatre March 29 through April 14. Tickets are $25 to $35; call (617) 547-8300.