If you're about to dig into a mid-'90s "period piece" about a plain nebbish at a food additive company who decides to blow the whistle on his corporation's illegal price-fixing practices, well, you better get a few interesting people to bring this sort of story to the screen. With a leading man less reliable than Matt Damon and a director less colorfully unpredictable than Steven Soderbergh, a flick like this could play like a well-meaning but hopelessly yawn-worthy docu-drama. Happily, since The Informant! boasts both of those filmmakers (and a big handful of others), it turns out to be a seriously entertaining film ... about a seriously plain man.

Damon plays Mark Whitacre, a high-ranking suit for a chemical company called ADM. Essentially, these guys create all sorts of wonderful food additives, and the focal point this time around is a corn product called lysine. Only problem is that ADM and virtually all of its executives, not to mention their competitors, are knee-deep in a global "price-fixing" scheme, which (in case you didn't know) is all sorts of illegal. But while Mark seems more than willing to narc on his colleagues, simply because it's the right thing to do, it quickly becomes evident that our semi-hero is hiding more than a few skeletons inside his own closet. Plus, as humorously realized by Damon's frequent inner monologue, Mark Whitacre is clearly a very naive man. And probably bipolar, too. Based on actual events and a book Kurt Eichenwald, and adapted with slyness and subtlety by screenwriter Scott Z. Burns, The Informant! is a tale of '90s-era corporate malfeasance that, quite successfully, aims to be a '70s-era boardroom thriller in the vein of Sidney Lumet or Alan J. Pakula. (Plus it features a fantastic Marvin Hamlisch score that is both playful and strangely old-fashioned.)

And while The Informant! will most certainly end up residing in the comedy section, don't mistake it for a fall-down laugh riot of any sort. The film has a dry and laconic demeanor, but it's (mercifully) lacking in "set up, punch line, repeat" machinations. Most of the humor comes from Matt Damon's quietly odd performance (his frequent inner monologues are quite randomly amusing), and much of the fun is derived by watching the corporate noose slooowly slither its way around Whitacre's neck.

Bonus points for a few unexpected twists in the tale, a great supporting performance by Scott Bakula as a noble fed, and just enough quirk to keep things from getting too dry. Fans of the reliably eclectic Steven Soderbergh will find The Informant! a "happy medium" between the filmmaker's "star-laden" Hollywood flicks and his smaller, yes slightly brainier, movies. And obviously that's a good thing.