Robert Longstreet and Alexia Rassmussen in "The Missing Girl"

Within the first half-hour of “The Missing Girl,” you actually wonder whether A.D. Calvo made a mistake in titling his latest feature in a way that perhaps promises a kind of potboiler that never arrives. When introducing the film at Fantastic Fest, one of the festival’s programmers felt compelled to note that “This isn’t usually the kind of film we book” since it would feel more at home at Sundance than it would at a festival tailored to genre fare. Yet Calvo has created a mystery that’s far more satisfying than any whodunit, a special film that leaves the audience wondering about the characters long after the plot has been resolved.

You know from the opening seconds of “The Missing Girl” you’re in good hands as Calvo enters Mort’s Comic Book Shop, a mildly trafficked store on a lonely street in a small town. Though Mort (Robert Longstreet) would stop you from calling it a toy store, you’re first introduced to still figurines that the middle-aged collector/owner is only slightly more mobile than, at least emotionally. As we learn gradually, there’s reason for that, and not the usual manchild justifications that are usually offered up in films such as these, but he is pushed out of his comfort zone ever so slightly by a new employee named Ellen (Alexia Rassmussen), a comics artist who can sketch away in between checking auctions on eBay. While he can’t afford to pay her, Mort clearly enjoys her company, despite frequently slipping into his taciturn ways, yet when her car breaks down as she’s on her way to New York to seek out a job opportunity she never discusses with her boss, Mort takes it upon himself to track her down, drawing from what little he picked up from his father, who was once a detective.

Alexia Rassmussen and Robert Longstreet in "The Missing Girl"There are two things that immediately stand out in “The Missing Girl”: the fundamental decency of all its characters — even Skippy (Eric Ladin), a high school rival of Mort’s who is the closest thing to a villain in the film, is at most someone lacking in manners and misspeaks at the wrong time — and the attention to detail in every aspect. Besides all the careful and thoroughly considered character work that Calvo and his actors put in, the writer/director nails the small talk between work colleagues, family members, and even shady car dealers (an auspicious cameo from Kevin Corrigan). Cinematographer Ava Berkofsky always seems to have the exact right shot selection to get the most out of the frame, whether it’s trapping Mort in nostalgia with the toys around him in his store or isolating the characters in small town life with her canny use of negative space, and the film brings in both a color palette that’s reactive to the characters’ mood and a use of split-screens that give a nice little visual jolt of energy.

“The Missing Girl” is so nuanced that it exposes a few of the more obvious story mechanics such as the way in which Ellen meets Skippy and Mort’s relationship with a local officer (Sonja Sohn). But these are easily excused when a film is working as beautifully and effortlessly as this. No matter what the size the part, every character has a dimensionality you rarely see in what becomes a true ensemble piece and the actors really seem to add to what must’ve already been on the page, with Longstreet in particular shining in a semi-tragicomic role. Calvo clearly trusts the presence of veteran character actors such as Sohn, Shirley Knight (as Mort’s mother) and Thomas Jay Ryan (as Mort’s brother) to do much of the heavy lifting and the relaxed rapport between them all is a pleasure to watch. Given the trajectory of Mort’s life, you wouldn’t expect the say the same of “The Missing Girl” in general, but like its protagonist, it’s unexpectedly buoyant and full of delightful little surprises.

“The Missing Girl” does not yet have U.S. distribution. It plays once more at Fantastic Fest on Monday, September 28th at 11:30 am.