Who wants to see Slumdog Millionaire?

You do. You just may not know it yet.

About halfway through the movie an astonishing sound hits your ears: it's Orpheus singing a lament for his dead Euridice, and it's from Gluck's opera Orfeo ed Euridice, and it's the last thing you expect to hear in a movie that's been heavy on pounding, Indian pop music. But it reinforces the feeling that's been growing on you for about an hour, which is that you're watching a fairy tale.

This is a good thing to realize, because what you've been seeing is a completely engaging, sometimes hilarious, but also horrifying narrative of life among the street children of modern India.

Jamal (Dev Patel, who wins our hearts) is a quiet young Muslim teenager who is a contestant on the Indian version of Who Wants to Be a Millionaire? Though he can barely talk to the show's MC (Anil Kapoor, taking the role of Game Show Host to new depths of sleaze) Jamal knows all the answers, and quickly rises to the level of ten million rupees.

Before he can get to 20 million rupees (something over $4 million at today's exchange rate), Jamal is arrested on suspicion of cheating, because how could a chai wallah (tea server) at a call center know all this?

Now comes the first of the horrors, because the police torture Jamal, I mean to the point that you will not want to watch, and if you're unconcerned that the USA had to elect a new government to outlaw torture in our country again, you won't be after you see this.

After the cops decide torture isn't working the inspector gets actually interested in Jamal's story, as he explains how episodes in his childhood led to his knowing each of the answers. And here's where the movie's structure kicks in, with flashbacks that show us the life of Jamal, his brother Salim, and the girl Latika, who form a sort of Three Musketeers for survival in the slums. Their story could easily be labeled Dickensian for its non-stop mix of the comic and the horrific, a sort of Oliver Twist in Hindi. (Only about a third of the movie is in Hindi, and the subtitles pop up all over the screen in an attractive new way.)

Jamal and Salim have a mother who is killed in one of the anti-Muslim riots of 1992-93, but not before they have their first comic adventure, which involves the two brothers at ages about five and six, a Bollywood action movie star, and a mishap with a public convenience. My guess is peanut butter thinned with yogurt, and some mango chutney added for texture; see what you think.

After the loss of their mother, the kids make a precarious living as ragpickers in Bombay's mountainous trash heaps. (This was before the city changed its name, its architecture, and its image.) They are “rescued” by a handsome, kind young man who runs an orphanage where the kids are treated generously until they're trained to be prostitutes, or blinded to become street singers. Jamal and Salim escape the beast, but Latika is not so fortunate.

After working as illegal peddlers on India's extensive railroad system (which gives us a brief tour of the subcontinent's eye-popping landscapes), the boys, now about 11 and 12, end up in Agra, where they work as illegal guides at the Taj Mahal. In some of the film's funniest scenes, Jamal spins increasingly fantastical histories for the confused tourists, while his brother steals their shoes.

Here's where the Gluck comes in: an improbable but lovely performance of the opera in the courtyard in front of the Taj, while the boys work the grandstands. Orpheus' love is so great that he will descend to the Underworld to claim his dead wife, and could the theme of the myth have anything to do with our story?

Jamal, who has never forgotten Latika, insists they go back to find her, so they return to Bombay, which is now Mumbai, with high-rises going up where their slum used to be. But the Mumbai underworld has grown stronger, and Selim is soon seduced by power and money to become a lieutenant for Latika's new owner.

It was about here, with the hint from the opera, that I realized that director Danny Boyle and screenwriter Simon Beaufoy were spinning a fairy tale. I started listing the elements in my head: Hero, and unreliable brother, orphaned early; two warlords and an enslaved princess; hair-breadth escapes; a treacherous wizard (the game show host); and a huge treasure. And the fact that an avatar of the god Rama appears in an early seen should have clued me in.

The only thing I wasn't sure of was the happily-ever-after ending, as the final segment intercuts the stories of the gunfighter, the girl, and the guy with the 20-million-rupee question at such a pace that the tension becomes almost unbearable.

This is grand, sweeping, compassionate movie-making about people you come to care about. Hollywood used to turn these out by the carload until they got sidetracked by special effects, but maybe this will help persuade a producer or two that people are more interesting than droids.

Oh, and stick around for the end credits.