Raised on a tiny farm in a dirt poor area of rural Brazil, young Mateus (Malheiros) decides to take a job as laborer in Sao Paolo to help support his aging mother and family back home. When he and his six comrades arrive at the filthy junkyard where they’ll be living and working, it’s quickly evident that Mateus and crew are unwitting victims of human trafficking. They are all held captive and forced to toil long hours stripping cables for copper, without pay. Their boss, Mr. Luca (Santoro), treats them as subhuman when he notices them at all, except for Mateus, whose initial defiance makes an impression. Gradually, the smart, enterprising young man starts earning Luca’s trust. Mateus is given more responsibility, advancing over his fellow prisoners and earning special treatment. Will Mateus use his increasing freedom and authority to do the right thing?

Moretto’s gritty, potent drama forces us to examine up-close the horror and injustice of human trafficking, a global problem it’s tempting to turn away from in disgust. After a violent start, “Prisoners” morphs into a taut psychological thriller, focusing mainly on the subtly shifting dynamics between the proud, bright Mateus and the cunning, brutal Luca. We also witness how the initial allegiance among the seven victims turns to distrust and resentment as Mateus seemingly betrays them all for his own selfish reasons. The entire ensemble cast is compelling, and while both lead actors turn in solid performances,  Santoro is particularly memorable as the contemptible Luca. For a lean, mean thriller that packs a wallop and really stays with you, catch “7 Prisoners” on Netflix.