There is an almost magical scene in Emanuele Crialese’s “Golden Door” when, on a ship filled mainly with Italian immigrants on their way to America in the early 20th century, a mysterious English lady named Lucy (Charlotte Gainsbourg) asks an illiterate Sicilian peasant named Salvatore (Vincenzo Amato) to marry her.

We know nothing of her origins except that they must be (at least) middle class. She is educated, comparatively well-dressed, and speaks fluent Italian. Yet she has no passport and travels alone in steerage with the poor people. For reasons that are not clear, she thinks that attaching herself to Salvatore and his family (his mother, two brothers, and two sisters) will help her to be accepted as an immigrant when the ship docks at Ellis Island.

Salvatore, who has been smitten since the first moment he saw her, agrees at once to marry her.

“I’m not marrying you for love,” she warns him.

He looks puzzled. “Love? We hardly know each other. These things take time, right?”

“Yes,” Lucy replies, somewhat hesitantly. Salvatore then asks her for a lock of her hair. Once he has subjected it to certain spells or other treatments he has learned from his mother (Aurora Quattrocchi), who is known as a wise woman back home in Petralia Sottana, he will make her love him.

“I don’t believe in magic,” Lucy tells him.

“With time, I will teach you,” Salvatore replies confidently.

Obviously, Mr. Crialese thinks he can teach us too, with a combination of a vividly imagined set of characters and the techniques of magic realism. But he doesn’t quite bring it off.

Wisely, the director makes the magical element grow naturally out of the peasant superstitions that are everywhere in the Sicilian campagna, where we spend the first third of “Golden Door.” The movie begins with two men in bare feet climbing a rock-strewn mountain slope with stones in their mouths. At a cross on the mountaintop, they deposit the stones alongside others and ask for a sign that they should or should not emigrate. They then sit back to wait with complete confidence that a sign will be given.

I was immediately hooked. This is a film about the dream of a new world, but from our point of view it is the persuasive depiction of the old world that is new and exciting.

But there are some drawbacks. One is that the characters, though vividly realized, seem to inhabit only the world of the film and to answer to nothing in ours — which characters in the best movies must do. Part of the problem is that Lucy has no backstory and hence no motivation for what seems like distinctly odd behavior. We are driven back upon the conclusion that she is a kind of magical apparition, perhaps the sign that Salvatore has asked for. She is just the kind of thing that happens in the film’s world — not, that is, in the one we know.

This impression is only exacerbated by the magnetic presence of Ms. Gainsbourg on the screen. That impossibly prognathous jaw set atop that improbably slender form makes her a true jolie laide and makes me, at any rate, unable to take my eyes off her. And Ms. Quattrocchi, in the role of Salvatore’s mother, is almost Ms. Gainsbourg’s equal for charisma. Between them, the two women represent the two poles of Salvatore’s existence: the past and the future, Sicily and America, the old and new worlds. Yet so compelling are they that we are constantly tempted to forget any world beyond their own.

This seems to be the effect for which Mr. Crialese was trying. We see nothing of America in the picture except for the processing facilities at Ellis Island. The country remains as much our fantasy as it is the immigrants’, and the film takes advantage by introducing several fantastical interludes. These are a mistake.

One of the immigrants says he has heard that rivers of milk flow in America. Others have seen joke American postcards featuring giant vegetables. Thus, the characters are made to bob about in oceans of milk, or to confront carrots as big as themselves. At this point, the peasant magic has gone where I can no longer follow.

Yet when Salvatore has himself boosted up beyond the frosted glass where he can catch a glimpse of the New York skyline and says he wouldn’t mind living in the sky, or when he has his first taste of white bread and thoughtfully observes that it is like eating a cloud — these are moments to treasure along with the prospective magic of the union of Lucy and Salvatore. At these moments, you will believe.

jbowman@nysun.com