The Sixth Column(1970)

The Sixth Column is a science fiction film about two warring alien species who bring their conflict to Earth. Each race has assumed human form to wage battle on our planet, but they face a critical problem: they can only identify fellow aliens by wearing special glasses. The premise creates a tense game of cat-and-mouse as the disguised extraterrestrials hunt one another while hiding in plain sight among the human population. Without their glasses, the aliens are indistinguishable from ordinary people, forcing them to rely on the technology to navigate their hidden war. The film explores themes of identity and deception as the stakes of an intergalactic conflict play out on terrestrial ground.