In lieu of a traditional title card, Indivisible offers a corker of an opening sequence that begins with three young women walking home from the beach like hungover soldiers in soft morning light until a blue panel van displays the original Italian title: Indivisibili. In between, that trio of up-all-night party girls rhythmically walks past the window of our actual protagonists: conjoined twins Daisy and Viola, who've yet to emerge from bed. As Viola sleeps, Daisy touches herself — the two are physically identical, but at no point over the next 100 minutes will you confuse one for the other. All of this unfolds in just a few fluid long takes, as does the sisters' morning routine, which ends with them piling into that van en route to a performance.

The teenagers sing duets together on the birthday-party circuit, with the catchy "Indivisibili" serving as their crowd-pleasing encore. (Daisy, who wears a Madonna glove, would rather cover Janis Joplin.) They're played by Angela and Marianna Fontana — real-life sisters, though not actually conjoined; their joint performance in Neapolitan filmmaker Edoardo de Angelis' moving third feature was, along with Lily Gladstone's turn in Certain Women, one of the most pleasant surprises at TIFF this year. In the film, passersby touch the twins for good luck, their father handles their finances and a skeezy-looking manager tells Daisy he would "cut his own head off" for a woman like her — it all ranges from vaguely to overtly exploitative, with Daisy both more cynical about their plight and more hopeful about changing it. Viola, pious and passive, just wants to make it through the set list and keep everyone happy. Both actresses are remarkable in their screen debuts, which seem destined to attract just the sort of attention their characters receive.

The plot goes just where you'd expect it to: A big-city doctor informs the siblings that they can be surgically separated should they so choose. One wants the procedure, the other doesn't, and de Angelis does such a nimble, efficient job of differentiating his dual heroines that we know which will be in favor before either can voice an opinion. The co-writer/director is kinder to his leads than their father or would-be manager are, and not just because he treats them as two individuals who happen to be joined at the hip. Everyone they interact with treats them as a single entity, rarely bothering to speak to one at a time. We see this wearing on them, even as they hide their pain behind smiles and choruses.

De Angelis is also smart enough to know when to get out of the way and let their affecting dynamic carry the day — occasional dips into melodrama aside, Indivisible is above all else a mood piece humming with energy and marked by wondrous moments: a tattooed diva's rendition of "Ave Maria" at a little girl's communion party; Viola and Daisy backstroking to shore after a boat party where they're forced to decide whether to sink or swim. Like them, Indivisible is more than the sum of its parts.