The Outer Limits (1963)

Season 2

Episode 10: The Inheritors (1)

Four soldiers have been shot in the head by bullets made from the fragment of a meteorite. As a result, they have developed genius level IQs. Three of them have disappeared, one remains in hospital. Adam Ballard, Assistant Secretary of Science, believes the men have been taken over by an alien intelligence, and that they are working to bring some evil plan to fruition.