In the opening scene of The Constant Gardener, British diplomat Justin Quayle (Ralph Fiennes) sees off his wife Tessa (Rachel Weisz) as she leaves on a trip from which we know she’ll never return. At a Kenyan airstrip, activist Tessa is traveling with a Red Cross physician to a meeting without purpose; within a few days, both of them will be murdered. As Tessa heads to the plane, director Fernando Meirelles keeps the focus on Justin in the foreground, while Tessa’s shape dissolves into a blur amidst a blast of overexposed glare. That shot of a man watching his beloved disappear from his life is, quite literally, dazzling.

THE CONSTANT GARDENER ( * * ½ )Directed by Fernando Meirelles.Starring Ralph Fiennes, Rachel Weisz and Danny Huston.(R, 130 mins.) At the Northridge Cinemas, Century Cinemas Del Monte Center, Century Park Seven.

So it’s perhaps even more disappointing, after such a brilliant opening, to watch the film itself dissolve into a similar blur.

It didn’t have to be like that. Meirelles—the precociously talented, Oscar-nominated director of City of God—actually makes a wise choice early on by focusing not on novelist John Le Carré’s trademark international intrigue, but on the relationship between Justin and Tessa. He flashes back to their first meeting in London—establishing a tension between Justin’s company man and Tessa’s cage-rattler—and their impulsive decision to get married before Justin leaves for an assignment in Africa.

But this tale has other fish of another genre to fry. As Justin begins to probe into the events surrounding Tessa’s death, he begins to unravel suspicious dealings involving some of his government colleagues and pharmaceutical companies doing business in Kenya. He’s shipped back to England, and his life is threatened. It’s quite the set-up for an emotion-packed detective story.

Only the mystery, such as it is, doesn’t take particularly long to solve. By approximately the end of the first hour, it’s fairly clear who is in bed with whom politically, as well as the specific shady activities in which the pharmaceutical company is engaged

It’s true that in a sense, Jeffrey Caine’s adaptation uses the conspiracy as a red herring. The film is set squarely in the shadow of the current war in Iraq, and the title itself turns Justin’s hobby into a metaphor for people so buried in the minutiae of their lives that they’re unable to see the bigger picture. The Constant Gardener in theory becomes as much about Justin learning about himself as about harsh realities of global economics.

The problem is that everything begins to feel redundant during the film’s final hour. Everything of consequence there is to know about the players in the plot, we know. While Fiennes’ performance and Meirelles’ stylish direction provide some distraction, the repetition of the film’s political message—building up to the trite use of mournful tribal chants and a chest-thumping speech—becomes wearying.

It’s inevitable in the current political climate that some people will see artistry in The Constant Gardener just because they agree with its worldview. Yet there’s a difference between a worthy idea and a great movie. After that remarkable opening, the glare of his own good intentions blinds Meirelles to a story that keeps running in circles.