Arlington's Fountainhead Theatre is waging an uphill battle as it tries to match the definitive production of "Betrayal" staged last season by Alexandria's Port City Playhouse.

Fountainhead has mounted an entertaining version of Harold Pinter's spare 1978 chamber play about infidelity. But those who saw Port City's production won't find much new here and might miss some of what they enjoyed in the earlier staging. Port City Playhouse told the story, related primarily in reverse chronological order, in a taut and stylized manner, a psychological ballet emphasizing the unspoken dynamics at work when three intersecting relationships unravel under the weight of multiple layers of deceit and guilt. It was a compelling, emotionally searing experience.

Fountainhead's staging is a worthy effort, well directed and competently performed, but compared to the earlier production, directed by Leslie A. Kobylinski, it seems to exist more on the surface and lacks some of the nuance and spark that Pinter created in the subtext.

Fountainhead director Sarah Denhardt concentrates on moving through the story line, a soap opera that takes place with a woman, her lover and her husband in London. It begins with an awkward meeting of the lovers several years after the end of their entrenched, seven-year affair and moves back through time until the illicit relationship's beginnings are reached at the end of the 1-hour 15-minute play.

Denhardt carefully paces the story's flow, allowing the many facets of betrayal at work to be revealed in a deliberate but natural manner. A love triangle is at the center of the story, and while others are obviously involved with their lives, we meet only Emma, her lover, Jerry, and her husband, Robert. Just within this simple polygon are numerous rings of pretense and infidelity, leaving no room to introduce other players in these characters' lives. For instance, Jerry is a close friend of Emma's husband, who has his own secrets, including the fact that he had known of the affair for years but did not tell Jerry. Emma has not always been honest with Jerry about her relationship with her husband, and it is hinted that Jerry feels misled because Robert never told him, as a close friend might, that he, too, has been unfaithful. Emma is distressed upon learning that Robert has strayed, and Jerry feels betrayed by Emma when he learns that she spilled all to her husband. We never meet Jerry's wife and can only imagine what she has been doing.

Denhardt allows her actors to occasionally exaggerate the terse and understated nature of Pinter's dialogue, working some of the lines for laughs. It's tempting to do so, but overemphasis on creating punch lines tends to break the fragile spell Pinter attempts to create. The playwright allows chuckles, but they should originate in bitter and subdued irony.

This production is most notable for the performance of Fountainhead regular Charlotte Akin as the pivotal Emma, traversing considerable emotional territory as wife and mistress, mother and mother-to-be. In their early scenes together, Akin and Dan Via, as a somewhat hard-edged Jerry, are both slightly mannered, but Akin grows her character's contradictory emotions as the story goes backward. When Emma hands Jerry the key and leaves the apartment they have used for their trysts, Akin's face is a portrait of clashing and very deep emotions. Akin brings to life a woman who is buffeted by incompatible feelings of guilt and desire, vulnerability and disenchantment.

Jim Jorgensen gives us an arch but low-key Robert and, as always, it's enjoyable to watch this nimble actor at work. It is Jorgensen's cool demeanor that helps us understand that the reality of betrayal might lie mostly in the view of the beholder.

"Betrayal," performed by Fountainhead Theatre, continues through Sept. 11 at Theatre on the Run, 3700 S. Four Mile Run Dr., Arlington. Showtime is 8 p.m. Thursdays, Fridays and Saturdays, with Saturday matinees at 2 p.m. For tickets or information, call the box office at 703-920-5923 or visit www.fountainheadtheatre.com.

Above, Charlotte Akin and Jim Jorgensen as a married couple dealing with infidelity in Fountainhead Theatre's production of "Betrayal," Harold Pinter's spare 1978 chamber play about a love triangle. Below, Akin with Dan Via.