Colombian drug traffickers have industrialized a new smuggling method: submarines built by hand in jungle camps, some running up to 30 meters long and capable of moving several tons of cocaine in a single crossing. The film follows U.S. Drug Enforcement Agency agents and the Colombian military as they hunt for construction sites hidden in remote jungle, territory with at least 300 known cocaine finishing labs and an unknown number of sub factories, where malaria-carrying mosquitoes and armed narco-traffickers make the search itself dangerous. Investigators estimate dozens of these vessels already run the route between Colombia and Mexico, with as many as 70 more expected to be built within a year. The centerpiece is a captured sub, inspected up close, its hull and ballast systems built without shipyards or blueprints, evidence of how much money and engineering effort the drug trade will spend to stay ahead of interdiction. The footage stays close to the search teams on the ground rather than reenactment, tracking one seizure as a stand-in for a much larger, mostly invisible fleet.