Tom McCarthy’s “The Station Agent” is a film as small as its protagonist, who happens to be a dwarf, but it’s also as compelling and charming as the remarkable Peter Dinklage makes the lead character. The veteran actor, so memorable from a scene in “Lost in Oblivion” in which he complained of little people being employed indiscriminately by directors to create a short-hand surrealistic effect, must take special pleasure in here playing a guy who may be isolated, but is neither cute nor tormented–instead being simply determined to live as normal and self-sufficient a life as anyone with a obsessive love of railroads can. It’s a lovely performance in a picture that, while flawed, is overall a deeply satisfying story of friendship and emotional redemption.

Finbar McBride (Dinklage) is first seen as an employee in the Hoboken model train shop run by the aging Henry Styles (Paul Benjamin). Intense and pretty much oblivious to the larger world–he dresses in black suit-and-tie to go to work (as does his boss), looking like a Mormon missionary, and simply ignores the occasional taunts of neighborhood kids as he walks by–his only diversion is his interest in railroads, of the real as well as the hobby variety, and his sole companionship consists of like-minded fans. When his boss suddenly dies and the shop is scheduled for liquidation, Fin finds that Henry has bequeathed him a small piece of land in a rural New Jersey town named–just a mite too obviously–Newfoundland; the plot is the site of an abandoned depot on a deserted slice of track. He packs up his few belongings, makes his way there and sets up house in the station; the remainder of the film is about how this quiet, undemonstrative fellow, given to solitary walks along track and long waits to catch glimpses of passing trains, gradually gets involved in the lives of some of the residents, normal-sized people who, it turns out, have their problems, too.

There are Cleo (Raven Goodwin), a lonely little neighborhood girl, and Emily (Michelle Williams), a pretty young librarian with an obtuse boyfriend and, as it turns out, a delicate condition. But more prominent are the two individuals with whom Fin reluctantly grows close: Olivia Harris (Patricia Clarkson), a troubled divorcee haunted, as we learn, by the loss of her young son, and Joe (Bobby Cannavale), a loquacious young fellow who parks his father’s hot dog stand near Fin’s depot and waits impatiently for the occasional customer or–more importantly–somebody just to spend time with. What “The Station Agent” is about, ultimately, is how Fin helps each of them, in much the same way that, in the old days, the fellow manning the depot served the community. But what’s special about the film is that Fin’s not depicted as some sort of pixie spreading magic dust all over the place; he’s as damaged as they are, but never inclined to give in to his troubles, and his involvement with them is hardly voluntary–indeed, he has to be dragged into contact. It’s the gentle, unsentimental approach that makes the piece so disarmingly winning.

That’s why the occasions on which it takes a more melodramatic turn seem so out of place, although even here the failings are to some extent minimized. One worries that Cleo’s invitation to Fin to talk about trains at her school will turn cloying, for example; but as Dinklage and McCarthy play it, it avoids the pitfall. And a scene in which Olivia’s ex-husband unexpectedly turns up at her place one morning to find Fin and Joe there–the only occasion on which they’ve stayed the night, entirely platonically–is mitigated by Cannavale’s marvelously chatty, unapologetic manner. But even Dinklage can’t save a misconceived episode in which Fin gets drunk in the local bar and berates the other customers for staring at him.

But happily such moments are rare, and the performances are so good that one finds them easy to forgive. Dinklage, who gracefully depicts Fin’s gradual emotional thaw, grounds the film beautifully, but Clarkson and Cannavale match him. She’s been widely seen lately–and widely praised–but she’s never been better, handling Olivia’s goofiness and profound sadness with equal skill. And Cannavale is a revelation as the garrulous, good-natured Joe; the sense of joy as he joins in Fin’s passion is so great that when Fin inevitably turns on him, the pain is all the greater. It’s an amazingly natural and delightful turn. Goodwin, Williams and Benjamin have less opportunity to shine, but seize on them.

“The Station Agent” is technically a very modest film, obviously made on a meager budget, but the behind-the-camera contributions are all at least adequate, and the unobtrusive style actually serves the picture’s understated tone. Generous and touching, but with a wonderfully sly sense of humor, this is a diminutive movie with a big, yet unsentimental, heart.