When the commander of a squad of rag-tag teenage guerrillas calls them monkeys or scamps — Monos,in Spanish — he might as well also be addressing the movie's viewers. Director Alejandro Landes thrusts the audience into the action, making his second feature as immersive as the moist climes where it's set. To watch this fierce drama is to be welcomed to the jungle.

Shot with agile handheld camera, Monosplaces the spectator as close as possible to the mud-caked, mosquito-swarmed events. The sight lines are anything but omniscient, and often blanketed by fog or blocked by vegetation. Changes in image quality or camera position are always integral to the story's viewpoint, coming when a character dons night-vision goggles or hops a ride out of the rainforest.

Landes is Colombian, and the movie was shot in remote areas of his homeland, but viewers could identify the film's unnamed setting with other Latin American nations scourged by civil war. The band of children are a rebel army of some sort, outfitted with automatic rifles. Their objectives are no more clear than their location. Meetings in which the kids are required to inform on each other reflect Marxist-Leninist tactics, but no specific ideology is articulated.

The monos are identified only by nicknames, including Wolf (Julian Giraldo), Bigfoot (Moises Arias), Dog (Paul Cubides), Lady (Karen Quintero), and Boom-Boom (Sneider Castro). Identities are sketchy and backstories untold. It's not immediately clear that one kid who becomes central to the story, crop-haired Rambo (Sofia Buenaventura), is female.

The monos engage in basic physical training and a fair amount of adolescent carousing, including a shocking assault that turns out to be a celebration. Their one continuing task is to guard an American hostage (Julianne Nicholson) they call "Doctora." Sometimes the kids supervise phone calls or video shoots designed to demonstrate that the prisoner is still alive. Exactly why they shouldn't kill her is information that apparently has not been shared with the lowly recruits.

Doctora (whose name and profession are casually revealed near the story's end) makes a few escape attempts. But the kids's worst crisis comes when one of them shoots randomly into a nearby field. This causes a serious mishap and changes in both leadership and location. The monos' often-absent commanding officer (actual ex-guerrilla Wilson Salazar) orders them off a misty mountain and into the humid lowlands, where discipline further unravels and the kids turn on each other. One inspiration for the script, written by the director and Alexis Dos Santos, is Lord of the Flies.

Before they're sent downhill, a few of the child soldiers experiment with hallucinogenic mushrooms. The incident isn't significant to the movie's episodic plot, but the trip does embody the overall drugginess of the monos' experience. The kids exist in the moment, without apparent goals or motives, overwhelmed by physical sensation.

Greatly assisted by Mica Levi's force-of-nature score, Landes seeks to take viewers on a journey that's nearly as intense as the one he depicts. He succeeds so well that it almost doesn't matter that the movie has no apparent greater purpose. Much as two of its characters do, Monos just slips into the maelstrom and lets itself be swept away.

Copyright 2021 NPR. To see more, visit https://www.npr.org.