Spacey plays Larry Mann, an aggressive, cynical salesman for Lodestar, an industrial lubricant manufacturer. He swaggers into a hotel in Wichita, Kansas, where the Midwest Manufacturers' Annual Convention is taking place, in hopes of landing the business of a giant Chicago firm. Larry has been preceded by longtime colleague and mentor Phil (Danny DeVito), who has organized Lodestar's presence at the convention -- downright ineptly, to Larry's taste. While all the other companies are holding grand affairs in the ballrooms downstairs, Phil has merely set up a tacky hospitality suite on the 16th floor, with a cheap tray of hors d'oeuvres for food.
It is clear that Phil, perhaps 15 years older than Larry and recently divorced, has lost the will to sell. While Larry seems to harbor genuine love for his longtime buddy, he is still burning with testosterone-fueled ambition. Larry knows how to deal with Phil, but he is less prepared for the third member of their team, Bob (Peter Facinelli), a wide-eyed rookie from the research department who has been sent to the convention to explain the technical aspects of the company's wares. Bob is pleasant enough, but humorless and deadly earnest -- precisely the opposite of Larry -- which serves only to provoke Larry into coruscating verbal attacks. Phil, whose emotional exhaustion could pass for mellowness, halfheartedly defends the young guy.
The tensions in the room escalate as all three await the arrival of the executive they want to court -- a.k.a. "The Big Kahuna," a.k.a. "El Kahuna Grande," as Larry at one point calls him. It doesn't take a crystal ball to realize that it's Bob, the green kid with no apparent sales skills, who is going to be the one to snag The Big Kahuna's attention. Only slightly less obvious is that Bob, who has been established as irritatingly pious, is more interested in selling Jesus than industrial lubricants.
Rueff and Swanbeck have added a few brief fantasy sequences, as well as some insignificant scenes outside of the hospitality suite, but for the most part The Big Kahuna is a three-person play masquerading as a movie. That's not always a bad thing. Some plays -- Who's Afraid of Virginia Woolf, The Balcony and No Exit, for example -- depend on a sense of claustrophobia; even minor "opening up" of the action dissipates the power. While The Big Kahuna may be one of those plays, it doesn't have enough power in the first place to make a strong claim on our attentions. Rueff's ability to draw characters isn't all that deft; Larry seems like a watered-down, bourgeois version of the kind of motormouth David Thewlis portrayed so brilliantly in Naked; Phil is an undefined vat of weltschmerz; and Bob is simply a priggish dork.
Spacey is the main reason to watch; as is always the case, even in his less compelling films, he manages to impress through sheer force of talent. But there is way too little else going on here.