Adapted from an original web seriesa phrase unlikely to be bandied about much in the near futureUndercover Brother nakedly aspires to be a black Austin Powers: International Man Of Mystery. Like Mike Myers' franchise, Undercover Brother is a culture-clash comedy pitting a special agent epitomizing the flamboyant and sexually liberated past against the comparatively dry and joyless present. The filmmakers even went so far as to recruit Michael McCullers (who co-wrote both Austin Powers sequels) as a writer. Considering Powers' success, Undercover Brother's appearance isn't surprising, but its quality is. Co-written and executive-produced by novelist John Ridley, who created the web series, Undercover Brother stars Eddie Griffin as an ace special agent whose wardrobe and sensibility never made it past the blaxploitation era. A warrior for peace, justice, and the right to get down, Griffin is recruited by the mysterious B.R.O.T.H.E.R.H.O.O.D. agency to fight "The Man," that shadowy figure of patriarchal white oppression who has long worked to preserve the status quo. Director Malcolm D. Lee (Spike Lee's cousin) previously directed the winning buppie comedy-drama The Best Man, which only hinted at the flair for broad comedy he demonstrates here. Cleverly mixing social satire (most successfully with Billy Dee Williams' Colin Powell-like general turned fried-chicken guru) with inspired silliness, Undercover Brother walks a fine line between satirizing stereotypes and exploiting them. Not all the film's jokes work, but Lee maintains such a genial air of high spirits that it's easy to overlook the occasional groan-inducing gag. A brightly colored, live-action cartoon that races from scene to scene with infectious energy, Undercover Brother never wears out its welcome or belabors a gag. A brief running time helps, but the real key to its success is its supporting cast. Griffin struts his way through a star-making role, but he's upstaged by veteran scene-stealer David Chappelle, who scores many of the biggest laughs as a paranoid, pot-smoking conspiracy buff. Even Neil Patrick Harris connects as the agency's token white intern. ("Affirmative action," mutters bigwig Chi McBride, by way of explanation.) The film's only weak link is Denise Richards, whose wooden performance sucks much of the humor out of her scenes. Summer films generally brim with high-concept fare promising escapist fun, but Undercover Brother is the rare popcorn movie that delivers. High-spirited and kinetic, it's the most endearingly goofy low comedy since How High.