Writer/director Issa Lopez's uncompromising spirit gives this genre entry real teeth.

The Mexico-set “Tigers Are Not Afraid” begins with young Estrella (Paola Lara) surviving a shooting on her elementary school by a drug cartel.

Later, we learn that Estrella and many kids like her are orphaned and living alone in empty buildings hit by hired gunmen. With no parents around, Estrella and friends are forced to work together to survive. Both poverty and cartel enforcers with itchy trigger fingers are a constant obstacle.

As a drug war rages and the children become entangled by corrupt adults, their brutal realities and the possibilities of the spirit world bleed together.

A supernatural element literally creeps into the film. A snake-like entity, visible only to Estrella, enters the frame. As the story progresses, a blend of horror and fantasy elements casually intertwine with the narrative.

Writer/director Issa Lopez has not made any of this watered down or carefully accessible for a mainstream audience. There’s a thick darkness present in the mood long before the ghosts show up.

While “Tigers Are Not Afraid” made a big splash at film festivals two years ago, it’s no wonder why it took so long for it to receive a proper theatrical release. This is a grim, unique take on life amidst a crime-ridden city, in which children are both the victims and the savage warriors left standing in the wake.

In addition to being a word of mouth hit that is finally making its way to theaters, “Tigers Are Not Afraid” also has allies in Guillermo Del Toro, Stephen King and Neil Gaiman.

Their endorsements are as potent a thumbs up as the “I have seen the future of horror…” accolade that King once gave “Hellraiser.”

The King connection is apropos; the title reminded me of “There Be Tigers,” which is among the very first stories King ever wrote. That short story follows a tiger that waits within a scary children’s lavatory and eats whoever goes in there. Moreover, King has depicted in varying works the gathered strength of children taking on literal and figurative grownup monsters.

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While the supernatural aspects allow for some striking (if not overly showy) imagery to take center, this film overall is stronger when its grounded in “reality” more so than when its exploring the fantastic.

Scenes of the children being pursued, beaten or worse by adults makes this closer in some ways to “City of God.” Del Toro’s influence is obvious, as the clearly established blend of harrowing adult monsters and magical realism brings “Pan’s Labyrinth” to mind.

Del Toro’s film (and approach to the genre overall) is far more consistent and concentrated than anything here, though.

FAST FACT: Issa Lopez and Guillermo Del Toro are joining forces on a new, as-yet-untitled, werewolf-western hybrid.

The concluding scenes contain some powerful imagery, but the ending of “Tigers Are Not Afraid” is far too pat and tidy. At times, the film is more impressive for what it aims to achieve than the overall result.

Where it ends up left me wanting more in terms of true closure, though Lopez never hesitates to take the story in directions that are bold for their cruelty and anti-mainstream pandering.

The uncompromised nature of “Tigers Are Not Afraid” is its best attribute and why it lingers in the mind afterwards. Lopez is clearly a serious talent to watch out for. Here’s hoping her follow-up hits just as hard and continues her path as a rare filmmaker to explore the human possibilities within the horror genre.

Three Stars