It's only two weeks since I reviewed "American Psycho", but here already is a more powerful movie dealing with similar themes, without the dumb gags or vicious streak. "Boiler Room" is often a comedy, because it lets us spend time with some of the most risible people alive -- stockbrokers. It's also a very serious thriller, because the protagonist gets seduced by their money-grubbing lifestyle and ends up in over his head.

His name is Seth (Giovanni Ribisi), a 19-year old New Yorker who dropped out of college and supports himself by running an illegal casino out of his apartment. When his father, a federal court judge, discovers this, he hits the roof, and tells him to get a proper job. Seth can't handle dad's disgust. He determines to find an occupation that requires him to wear a suit.

Then one of his friends sets him up at the firm of J.T. Marlin -- a telemarketing 'chop shop' that sells people stock for companies that don't exist, then charges them huge commission rates to dump it on the open market. This is more dishonest than the casino, but hey, it looks respectable enough. And it pays better. That's made clear in a pep talk by the recruiter, Jim (Ben Affleck), who seems to have used Alec Baldwin's chilling monologue in "Glengarry Glen Ross" as a self-help tape. "Work here," he tells the men in front of him, "And within three years you'll be a millionaire. Anybody who says money is the root of all evil doesn't have any."

The guys know Oliver Stone's "Wall Street" off by heart, too. They proudly recite the villain's speeches; oblivious to the message, and getting a kick out of the lingo. When they're all on the phone, screaming stock pitches to potential victims, the obsession and aggression in the office is palpable, and so very evil and illegal that we know something disastrous is bound to happen.

Since we are so engaged by Seth, we watch this with more tension than disgust. He is a well-written hero for the piece because he's an essentially good kid; we can sympathise with his desire to make money, and though he does dishonest things, he doesn't realise it, because he hasn't evaluated the situation in that way. The climate in J.T. Marlin teaches him to consider only money, and if there's nothing wrong with the pay check, what could be wrong at all? Seth has to be suckered in before he can realise what a sham this is, and "Boiler Room" is fascinating because it lets us see the whole process unfold.

All of the movie's dialogue is impressive. Brokers' conversations sound like a cross between financial jargon and military planning. And Seth's scenes with his father (Ron Rifkin) and the film's love interest (Nia Long) are staged like clichés but played with humour, emotion, presence and personality. The characters talk about their backgrounds, hopes and needs in convincing ways. "Boiler Room" works as a morality play by presenting us with people whose moral compasses it's actually possible to care about.