Stop right here if you plan on seeing the movie. I'm going to spoil a few things, if not plot details, at least the emotional ride that is best experienced first hand. To begin with, the film is incredibly engulfing. It's almost impossible not to get drawn in as you experience the childhood scenes of young vagrant Jamal and his brother, Salim. The story is structured around Jamal's amazing success at the Indian version of "Who Wants to be a Millionaire." Because he's just a street rat (scoundrel! take that!), the unctuous host hands him over the authorities for interrogation on suspicion of cheating. Great premise, interesting set up. The frenetic energy pushes the film along and you get invested into the story. All great stuff.
That's why it's so jarring when during the last third of the movie, you have to suspend your disbelief so much in order to make everything work. I felt like the movie was like the Tower of Terror, a slow rise to the top, a thrilling climax, and then a drop that makes you want to yack when hitting bottom. Character's motivations fly out the window, too many coincidences occur, and it becomes clear that this isn't just fiction but a fairy tale. And the game show gimmick tires a little bit, even if it's deftly done. I want to wholeheartedly recommend the movie and give it an enthusiastic thumbs up but the ending confused and flabbergasted me a little too much. It's still a worth a watch though.
One of our friends (who hasn't seen the movie yet) said that it was supposed to be the most convincing portrayal of life in the Indian slums. Since I don't know anything about that particular subject, I'll take her word for it because the movie did seem quite realistic in that sense.