Despite the exotic nature of its foreign locale -- the teeming, impoverished streets of Mumbai, India -- "Slumdog Millionaire" is every inch a Danny Boyle film.

The hope within the squalor, the humour within the violence, they're all thematic trademarks of the British director of the druggie drama "Trainspotting" and the zombie saga "28 Days Later." Only this time, Boyle takes his wildly high-energy visual esthetic and applies it to a story that, at its core, is really rather sweet and traditionally crowd-pleasing.

The unassuming Dev Patel stars as our slumdog underdog, Jamal, an 18-year-old who comes from nothing but is on the verge of winning more money than anyone's ever won before on the Indian version of "Who Wants to Be a Millionaire?" The game show's host (an ideally smarmy and egotistical Anil Kapoor) grows unshakably suspicious as Jamal prepares to face one last question for the top prize of 20 million rupees and has him hauled in for police questioning (by the ever-imposing Irrfan Khan).

Simon Beaufoy's complex script, based loosely on the Vikas Swarup novel "Q & A," glides effortlessly among Jamal's interrogation, his unlikely success in the television hot seat and his rough-and-tumble upbringing, which provided the life lessons that serve him so miraculously well now.

Jamal reflects upon the desperate times he shared with his older brother, Salim (Madhur Mittal), after their mother was killed in a savage anti-Muslim attack. He remembers the cruelty of the Fagin-like figure who forced them and other orphans into slavery. And he recalls fondly the time he spent with Latika (stunning former model Freida Pinto), his first love who, as a scared child, became the brothers' third Musketeer. (Loveleen Tandan, who cast the film -- including the three sets of actors who play the main characters at various ages -- did so much behind-the-scenes work, she gets a co-director credit.)

Maybe it's a bit too clever that every question in the game show just happens to have some connection to Jamal's vividly Dickensian life, from his encounter with a blind child panhandler to the unfortunate reason he knows what a Colt .45 is. But that's the point: witnessing the uplift of the charmed new life Jamal can now call his own.

"Slumdog Millionaire" won't let him forget where he came from, though. The mad dashes through Mumbai's most cramped corners provide a dizzy thrill with their off-kilter camera angles, despite the dismal scenery (in that regard, the film shares an inescapable bond with Fernando Meirelles' equally unflinching "City of God"). Occasionally, though, Boyle will take a moment to catch his breath -- and let us catch ours -- as he does in a striking overhead shot of the patchwork of tin roofs under which these children make their makeshift homes.

The cinematography from Anthony Dod Mantle (who also shot "28 Days Later") gives even the most depressing images an unexpected beauty, with Chris Dickens' expert editing keeping the considerable action moving fluidly.

But then in the third act, "Slumdog Millionaire" takes an unfortunately conventional turn, when everything until then had felt so fresh and new. The mob bosses who rule Mumbai, and with whom the arrogant Salim has aligned himself, are depicted as singularly snarling caricatures. And the relationship between Jamal and Latika, delicate as it is, reveals them to be little more than a familiar pair of star-crossed lovers trying to find their way back to each other. Nevertheless, realism permeates even that aspect of the film: She's pragmatic, he's romantic.

The absolute ending is a joy, though, so please make sure you stick around for it. After all the heavy, emotionally wrenching material that preceded it for two hours, it's the perfect final answer.

Three stars out of four.