Darwin’s Nightmare is a good example. Directed by the Austrian filmmaker Hubert Sauper and nominated for an Academy Award in 2006, the movie describes the destructive train of events set in motion when, in the 1960s, the Nile perch was introduced into Africa’s Lake Victoria. A voracious species, the fish quickly devoured most other life in the lake. After its flavorful white meat was discovered in Europe and Japan, demand for the fish boomed, and the perch trade flourished. In one of many powerful images, Darwin’s Nightmare shows giant Soviet-era cargo planes touching down on a runway in Mwanza, a town on the Tanzanian shore of the lake. Taking on fifty-five tons of the fish, they’re barely able to lift off. Meanwhile, the bellies of the locals go unfilled. The film offers a harrowing look at the collateral damage of the perch trade—the sad-eyed street prostitutes who service the Russian pilots; the destitute families of fishermen who succumb to either aids or the crocodiles in the lake; and, in one of the most disturbing scenes I’ve ever seen on film, the filthy, festering open-air pits where the maggot-infested carcasses of the filleted perch are dried and fried before being carried off for sale to locals too poor to afford the flesh of the fish itself.

While effectively evoking this bleak backwater, the film simultaneously explores reports that the cargo planes that fly in to pick up the fish arrive not empty, as local notables maintain, but filled with weapons for use in Africa’s endless civil wars. After various tantalizing clues are offered up, a Russian pilot finally confesses on camera that, on his flights down to Africa, he does indeed bring weapons with him, offloading them in Angola before traveling on to Johannesburg to pick up grapes for the return trip to Europe. So, the pilot says in his broken English, “the childrens of Angola received guns for Christmas, and European children receives grapes.” Explosive and wrenching, the revelation seems the final brilliant stroke in a piercing parable about the cruel logic of global capitalism.

Yet, as I watched, the old feelings of irritation and befuddlement began to rise. Darwin’s Nightmare uses no narrator, just the occasional intertitle to impart some shards of information, and the results are often confounding. At one point, for instance, the film shows some grainy clips of an ecological conference in Kenya where some platitudes are uttered about the quality of the lake’s fish, but these pass by so quickly that it’s hard to tell what’s going on. In describing the perch trade, the film shows the plant where the fish are packaged, but we’re never told how much the workers make or what broader benefits the plant may have produced for the community. The discussion of the arms-for-fish pipeline seems especially muddled. In his determination to avoid narration, Sauper at one point has a night watchman at a fish research institute read a few lines from an investigative article in a regional newspaper. The journalist who wrote the piece is interviewed, but in so fleeting a fashion that we can’t tell how he arrived at his conclusions. What’s more, the climactic admission from the Russian pilot seems to diverge from the one offered by the journalist—a variance that the film makes no effort to address.

Michael Massing is a contributing editor to CJR and the author of Now They Tell Us: The American Press and Iraq.