The camera opens on a pair of worn pink shoes with pretty pink bows. A cobbler is carefully restitching them. A young boy watches as he does.

Had he kept watching them, they never would have disappeared. And audiences never would have met The Children of Heaven.

The Children of Heaven works in much the same way as Vitorrio De Sica's The Bicycle Thief: a poor person loses a common but essential object, and suddenly that person's world is turned upside down and inside out.

Nine-year-old Ali (Mohammad Amir Naji) can't tell his parents about losing his little sister's shoes because his father can't afford to replace them and his mother, nursing an infant and suffering from a back injury, already is at a loss to keep the household going. So Ali comes up with an ingenious plan, or rather, several plans. In plan A, he and his sister wear his sneakers in shifts: Zohre wears them to school in the morning, then runs home so Ali can change into them and run back to school for the afternoon.

But problems arise when Ali and Zohre can't complete the exchange quickly enough and Ali gets caught sneaking into school late once too often.

So Ali has to move on to Plan B: a local marathon, in which the prize for third place is a brand-new pair of running shoes.

Along the way to the climactic race -- in which Ali dares not finish above or below third place -- writer-director Majid Majidi entertains us with a number of scenarios, as in what happens when one of Amir's sneakers slips away into a rain gutter or Zohre spots her old shoes on a classmate.

There's a trip to the wealthy side of town as well, when Amir's father decides to moonlight as a gardener. The lavish homes of Iran's upper class offer Majidi one more striking contrast to play with and a second set of stereotypes to play against.

But Children of Heaven is more than a tale of a poor family trying to survive in the tenements of Teheran, and Majidi is more than an astute storyteller. He's a careful crafter of images who goes to great lengths to capture the odd angularity of Teheran's narrow old streets and has even more fun with the darting fish in the courtyard basin where Amir's mother does the family's wash. Much of Majidi's story is told in these images, which only makes it that much more effective.

Like most moderately made films, The Children of Heaven has its faults. Amir Naji has a sweet smile and sparkling eyes, but his crying -- an essential plot element in several places -- seems as forced as it is overwrought.

And eventually you have to wonder why Ali waits so far from school to do the shoe switch; given the spot he's in, you'd think he'd be running in place outside the school door.

But nitpicking aside, Children of Heaven is a rare treat, a first-class look at life in the Third World and more: a reminder of how difficult life can be for those who have but one basket with one egg in it -- and how resourceful those without resources have to be.

Occasionally it may seem hard to follow, but hang in there. It's even harder to forget.