Save the Green Planet! (2003) on Netflix

A traumatized young man abducts Korean leaders, believing they're toxic reptilian aliens - a fifth column launching a takeover of beloved Earth. Stumped law enforcement geniuses half-seriously hire a disgraced, disheveled private detective with a long-ago history of super-crime solving. The alienated South Korean youngster Lee Byeong-gu builds an isolated basement command post/torture chamber/film studio to force the awful truth out of the slimy, uncooperative politicians and businesspeople, then alert the public. Byeong-gu is helped by his devoted girlfriend, who buys his theories, but wonders if his horrible childhood has colored his thinking.