Unearthly Stranger

Mysterious woman marries government scientist Davidson despite his lack of knowledge about her past. His bosses are suspicious of her unusual traits. After it's clear she does love Davidson, the pair come under attack.

Unearthly Stranger is a 1964 mystery horror movie directed by John Krish, starring Gabriella Licudi, John Neville, Patrick Newell. It holds an IMDb rating of 6.4/10 from 1,190 votes and runs 1h 18m.