The miracle of Steven Spielberg's "E.T. The Extraterrestrial," released this month on its twentieth anniversary, is that it isn't about extraterrestrials. We don't know where E.T. came from, why he's here (is he a he? a she? an it?), or any of the information that a lesser film would have been sure to give us. The film is in fact about a fragmented family in need of healing - dad is "in Mexico with Sally" - and the pain is apparent just in the way mom and the three kids gingerly step around the issue.

And then E.T. shows up - no cutesy names here, either - to the boy, Elliott, the middle child just on the cusp of losing his childhood fantasies but still willing to believe in spacemen if they're real enough. He has a complete set of "Star Wars" action figures and knows quite well that they are the fantasy ("See, they can fight!" he tells E.T.) Ten-year-old Henry Thomas, who plays Elliott, is a miracle of casting, a bright boy whose face is an open book and in whose mind we can read every thought as it happens.

So the film is the story of how this creature pulls the family together; first the children - Michael, the oldest (Robert MacNaughton), Elliott, and six-year-old Gertie (the absolutely scrumptious Drew Barrymore) - and then their mother, Mary (Dee Wallace-Stone), until the healing is complete with the return of E.T. to his spaceship.

What is also a miracle is the economy of the script, by Melissa Mathison, and the direction by Spielberg, which treats the story as though it were a documentary. Spielberg grounds the film in the very real subdivision where the family lives, a subdivision still under construction, pushing up and up the hill above a Los Angeles-like city, a bare-bones, unfinished community with dirt for yards but swimming pools already in the ground. And Mathison wastes no time on explanatory dialogue, trusting the images and her characters' own interactions to spell it all out for us. So we first meet Michael and his friends as they torment Elliott during a game of Dungeons and Dragons, which leads to Elliott's being sent out to pay the pizza delivery guy and thereby meet E.T. And Gertie, who accepts E.T. as real - why not? - dresses him in her doll clothes. Everything is as down to earth as our own lives, and every actor in the film behaves exactly as you and I might wish we would do in the same situation. If there is one moment of fantasy in the film it is the revolt of the frog dissectors in biology class - and I wonder if the miraculous rain of frogs in "Magnolia" owes its genesis to this film.

But without a believable E.T. the film would have little power, and give little pleasure. E.T. is human in size, he is imperfect (he gets drunk on the beer in the fridge), he is clumsy, and he is mortal. He barely shows us his supernatural powers, but what he shows is vitally important: he can make the dying live again (the flowers in the pot), he can make a spinning solar system out of balls in the house, and - the real magic - he can make bicycles fly. That is all Spielberg and Mathison need to give us, in this most exquisite film, in which a little magic goes a very long way.