By all rights, ''Dear Frankie" should be unbearably sentimental bilge. That's certainly how it comes across in the trailers. But this wee Scottish drama takes a mawkish premise and, by playing its cards close to the vest, imbues it with quiet, careworn dignity. The movie's still shameless; the difference is you don't mind.
Director Shona Auerbach, making her feature debut, is clever enough to understand that characters we have to meet halfway are always more interesting than those who throw themselves at us. Thus we're introduced to Lizzie Morrison (Emily Mortimer), a pretty but dour single mother restlessly moving from one town to the next around the Glasgow area. She's fleeing from the knowledge that she might be entitled to a little happiness, and in her wake she drags her ornery old Mam (Mary Riggans) and her 9-year-old boy, Frankie (Jack McElhone).
Frankie wants a dad, badly, and since the real one isn't available for reasons I'll not spoil, Lizzie has made up a father out of whole cloth. This make-believe Da is a sailor on the H.M.S. Accra, and he sends Frankie letters from around the world, with colorful stamps that go into a collection book while flagged pins go into the tattered Mercator map on Frankie's bedroom wall. It's only a matter of time, of course, before the boy will recognize his mother's handwriting.
Before that can happen, crisis looms: The ship is coming to port, and mother must provide a father or the jig is cruelly up. So she hires a total stranger and coaches him in all things Frankie. Now, if this were a studio film, the Stranger (which is how he's billed in the credits) would be played by Richard Gere or maybe Mark Ruffalo if we were lucky. This being a deceptively small British movie, we get Gerard Butler, in the first of what will doubtless be many karmic atonements for playing the Phantom in the most recent ''Phantom of the Opera."
I don't have to spell things out for you. ''Dear Frankie" acknowledges that this terse, handsome fellow is too good to be true and then dares us to scoff. Auerbach gives us a glum and economically prostrate Scotland that still seems flooded with beautiful afternoon light, and she has the novel idea to insist that fairy tales are possible, maybe even deserved. Certainly the wary wooing of Lizzie and the Stranger -- one step forward, three steps back -- flies in the face of what seems like a national distrust in happy endings.
There are complications, and there are ham-handed bids for our sympathy that a more seasoned filmmaker might have avoided. Frankie, for one thing, is deaf. He's a deadpan little lip reader, and the movie thankfully gives him some school chums for whom his affliction is just a personal quirk, like left-handedness. But the only reason he's deaf in the first place is so that our hearts will go out to him.
Then there's the soundtrack music: Alan Heffes's piano-driven original score and sensitive rock ballads by the likes of Damien Rice. They make for explicitly lovely movie music, and there's the problem -- you can feel it hustling your emotions this way and that.
Yet ''Dear Frankie" continually stops short of dumping the full load in our laps, and the denouement is both unexpected and gratifyingly slight. Auerbach gives Mortimer enough space to show how a woman might become a bad mom for very good reasons, and she lets McElhone be a kid, albeit one with the solemnity that comes from round-the-clock yearning. The Stranger remains a contrivance, but he's one you warm to, just as this innocently calculated movie comes to life in spite of its machinations. Audiences deserve fairy tales, too, and this one delivers.
Ty Burr can be reached at firstname.lastname@example.org.