It’s an old B-movie plot: a callow young guy is seduced by the lure of wealth and love and turns to the dark side, with unhappy results. The scenario is repeated again by Andrea di Stefano, but what makes his treatment of it more interesting than most is the fact that in this case the evil that sucks the protagonist in is a historical figure, Colombian drug lord Pablo Escobar. And he’s played with relish by Benicio Del Toro.

The protagonist of the picture, however, is a fictional guy named Nick Brady (Josh Hutcherson), a Canadian who’s come to the Colombian beaches in the late eighties to give surfing lessons. It doesn’t take long for him to fall for the local beauty Maria (Claudia Traisac), who turns out to be Senator Escobar’s niece. Soon they’re engaged, and Escobar will give Nick a job at his palatial estate. He also takes care of the gang of brothers who’d harassed Nick, his brother Dylan (Brady Corbet) and Dylan’s wife Anne (Ana Girardot) at the beach—with the most extreme prejudice. Nick’s not the brightest of bulbs, but even he begins to have qualms about the tactics of Pablo’s men, though Maria, still more obtuse, remains unwilling to accept the truth.

All this is presented in the form of a protracted flashback inserted between events of 1991, when Escobar is about to go to prison in a deal with the government following a near civil war and is making plans to stash his loot so that it will be waiting for him when he leaves jail. Among the trusted associates he chooses to drive crates of cash and diamonds to hiding places around the country is Nick, who’s assigned to meet with a man who will take him to a cave where the stuff can be stored and the entrance blown shut with explosives; he’s then to kill the man to keep the secret. Unfortunately, the man is ill and sends his young nephew Martin (Micke Moreno), who does his job admirably but whom Nick is loath to dispose of afterward.

That sets up the last act of the film, in which Nick has to face off against a slew of men in Pablo’s employ, most notably ruthless enforcer Drago (Carlos Bardem). This scenario just reinforces the fact that Nick is amazingly slow on the update—perhaps with his apparently limited schooling his unaware of the fate of pyramid builders—but worse it requires him to suddenly become not only a wily, street-smart guy but a pretty fair shot to boot. To say the last reel strains credulity is an understatement, especially since Hutcherson—who’s certainly persuasive as a boneheaded, lovesick cipher—can’t pull off the transformation into action hero.

Nonetheless the movie, as implausible as it grows, benefits from one strong element: Del Toro, who portrays Escobar as a seedily charming fellow whose sleepiness masks an underlying streak of cruelty and can abruptly explode with menace. Moreover, it situates him in a society that’s depicted like a South American version of Prohibition-era Chicago, where a strongman’s Robin Hood-like sharing of the wealth can make him a popular hero among ordinary folk, and give him a degree of economic and political power so great that he can feel free to challenge the so-called authorities with near-impunity. Del Toro’s performance is marked by what might be ironically called a flashy understatement, in which he rarely rants but always comes across as threatening even when he’s smiling. That he’s a fawning family man somehow makes him all the more frightening, and when toward the close he finally explains that he’s only following the law of nature, and indicates his strange relationship to God, it’s genuinely chilling.

It’s a pity that the rest of “Paradise Lost” isn’t worthy of him. Strip away the historical trappings—which one can certainly argue are tastelessly used—and there’s not much left to admire beyond Carlos Conti’s production design, Luis Sansans’ evocative cinematography, and Moreno’s turn as an eager young husband and father who doesn’t have an inkling of the trouble his uncle has gotten him into. “Escobar” gives Del Toro the chance to shine, but it just uses his portrait of a modern-day monster as backdrop to a pulp B-movie plot that Hutcherson isn’t equipped to carry convincingly.