I remember the first time that I saw this SF chiller was at a local drive-in theater in the late 60's as the second feature. I don't remember what the first one was--that's how creepy "Unearthly Stranger" was for me. For a low-budget film it has everything: wit, intelligence, excellent acting, compelling direction, and for it's modest budget more than adequate (minimalist) use of special effects. I've seen it a few times since on t.v., and just recently acquired a second or third generation copy on ebay. I was waiting for the scene where the professor's wife ( whom we already know is a tad unusual) goes for a walk into town and loiters near the public schoolyard, where the nine-to twelve-year-olds are playing. While standing there, the children, one by one, begin to take notice of her, and in a mass, start backing away from her...well, if you haven't seen it, what follows is worth the price of viewing by itself. A bit of info: many years ago a friend told me that this film was actually inspired by the SF novel "To Walk The Night" by William Sloane, originally published in 1938. When I finally got a copy, I was surprised how the closely the plotline of "Unearthly Stranger" hews to Sloane's novel. Hard to understand why the producers would fail to give credit where credit's due...at any rate, find a copy where you can, and pray for it's release on DVD!