The world feels as if it’s going to explode in “Topside,” taking place beneath the streets of New York in the furthest reaches of the MTA system where Little (Zhaila Farmer) has spent her five years on earth without ever coming up to the surface. Shards of light and sound break through the darkness of the subterranean lair that she shares with a few others — namely John (Fatlip), who generously offers her cereal when she wanders into his corner — and she largely spends her time entertaining herself with the limited electricity that can power an iPad for short stretches when she tires of investigating the various intrigues of the place that’s hinted at from above and always just out of her reach, waiting out each day until her mom Nikki (Celine Held) climbs down a grimy ladder from the subway station above as if descending from the heavens.

You never are conscious of the technical wizardry involved in Held and Logan George’s extraordinary feature debut, but the two create a rousing sensory experience that inspires the same sense of curiosity in its audience as Little is feeling herself, connecting the physically tactile to the emotionally intangible. With marvelously elusive sound design and Lowell A. Meyer’s expressive camerawork constantly recognizing the distance between the five-year-old and the world around her, every step is exhilarating when accompanied by putting yourself into the mental calculus of what to expect from one moment to the next, often having the unknown upend things once it presents itself. It’s as if the two have made their own version of “Gravity,” only instead of taking place in outer space, George and Held envision the world right in front of us anew, where the wonder inherent in Little’s perspective tempered by the consciousness of what it takes for Nikki to protect her that she couldn’t possibly know about as a child.

It likely was a necessity for Held to cast herself as Little’s mother, as much as it is a strong showcase for her as an actress, when “Topside” relies on her bond to Farmer, who is completely authentic in her reactions to an overwhelming world, particularly when city workers’ threats to clear Nikki and Little’s terra firma for construction finally appear real enough to drive them up to the ground level. The film draws considerable suspense from the two navigating the city when even the introduction of daylight is a harsh obstacle, let alone the scramble to find shelter without a penny to their name, but Held and George mine even more from the narrative’s unique dynamic of requiring Nikki and Little to spend more time together physically in the city, yet have increasingly disparate views of what’s going on when Nikki goes about her routine and Little is suddenly inundated with firsts, with her mother more fearful than ever now that the life she’s hardly proud of has to take place in her daughter’s sight.

Held and George’s recruitment of ace street casting director Jennifer Venditti, a key architect of the Safdie brothers’ immersive realities, and Rebecca Dealy, to fill out the ensemble that Nikki and Little meet along the way adds to the credibility that the directing duo are able to establish so clearly, drawing on years of research they conducted underground in the subway tunnels before making “Topside,” and the result highlights the anxiety that comes with every decision the less fortunate are forced to make as a matter of survival, choices that the privileged may not even ever have to encounter. When economic pressure has cut across borders, the way “Topside” builds compassion for the plight of its characters without ever feel condescending or trite is likely to travel just as powerfully and after starting in a place where people can’t be bothered to pay attention when traversing about busy lives, the undeniable pull to make you take notice is truly moving.

“Topside” will screen at the Venice Film Festival Film Critics’ Week on September 8th at 2:15 pm at Hall Perla and September 9th at 7:45 pm at Hall Astra 1 and 8 pm at Hall Astra 2.