So much is right about "The Interpreter" that it's easy to forgive the fact that the essential story is a static assassination plot whose climax hits with a dull thud instead of a sharp bang. For most of the way, it's a thoughtful melodrama crackling with sophisticated dialogue and understated suspense, a refreshing reverse of the bruising bombast of today's typical thriller.

The movie's first half presents a riveting dynamic between Nicole Kidman as a UN translator who overhears a death threat and Sean Penn as the chief fed on the case.

With the hush of their interaction and the film's subtle twists, "The Interpreter" is a welcome throwback to suspense yarns of the 1970s, which had a depth of character and intricacy of motive generally lacking now in Hollywood.

That's no surprise, since the director is Sydney Pollack, who made the first-class 1975 CIA thriller "Three Days of the Condor". Yet the team of three screenwriters ? including Steven Zaillian ("Schindler's List") and Scott Frank ("Minority Report") ? have mustered bottomless mood in support of a pedestrian narrative that never quite pays off. Kidman plays Silvia Broome, who grew up in the fictional African nation of Matobo, whose liberator-turned-despot, President Zuwanie (Bermudian Earl Cameron), is about to address the United Nations amid accusations of genocide against him.

One of those anonymous translators in the glass booths, Silvia overhears a cryptic exchange uttered in a rare language she happens to speak, which she interprets as a death threat against Zuwanie.

Federal agent Tobin Keller (Penn) and partner Dot Woods (Catherine Keener) lead the investigation, initially sceptical of Silvia's story and halfway convinced she has a hidden agenda of her own. As the agents gradually come to take the interpreter at her word, a fascinating bond develops between Silvia and Tobin, each bearing old or new emotional wounds whose symmetry feels a bit forced and convenient. Tobin's pragmatism collides with Silvia's idealism. His suspicious nature drives Tobin to question Silvia's sincerity. Her compassion prompts him to open his heart and perhaps overlook warning signs that Silvia is not the person she seems to be.

The restraint of Kidman and Penn's assured performances, coupled with the screenwriters' incisive dialogue, makes "The Interpreter" an engrossing affair for much of the way.

The supremely talented Keener turns the sidekick gig into an art form with her sly humour and easy camaraderie.

Pollack and his collaborators show admirable prudence on the action. When an explosion happens here, it's nothing much by contemporary Hollywood standards of the BIG BLOW-UP.

Yet nestled in a context where viewers have come to care about the characters, seeing them as real people rather than expendable extras, the blast has a more visceral effect than a mushroom cloud ten times the size in a bigger, dumber flick. The attention to brooding suspense and character definition make it all the more disappointing when the assassination plot plays out so limply. It's hard to invest emotionally in the urgency to protect a murderous dictator, and the ultimate revelations about who does and doesn't want to kill the guy have little dramatic impact.

The storytelling also turns lazy near the end. The film establishes at the outset that an innocent glitch such as a malfunctioning metal detector will prompt authorities to disrupt UN proceedings, evacuate the joint and send in the bomb-sniffing dogs. After that sequence, it's just silly down the homestretch to have the place crawling with feds convinced someone's about to pop Zuwanie, yet allow business as usual to continue.

Pollack did manage to negotiate his way into a location even Alfred Hitchcock could not secure for "North By Northwest". Hitchcock was denied permission to shoot inside the United Nations, but Pollack won over Secretary-General Kofi Annan and gained weekend and evening access, providing an intimate glimpse of one of the world's most private political strongholds.