Horror without Ghosts or Gore

How about The Fly. The original version was done without gore and scared the bejeezus out of me, too. Anything of the scientific nature that probably will happen in the near future, and be prone to serious error until the bugs are worked out (LOL), let's face it, that's terrifying.

Gerald's Game had a tad of gore--the protag removing skin from her hand to get the frickin' handcuff off but it didn't freak me out. Stoning can be gory but it wasn't wasn't explicit in The Lottery, and that didn't trip my trigger either though Shirley Jackson's 'We Have Always Lived in the Castle' still gives me a nice frisson. The old short, The Horla by Guy de Maupassant is a classic creeper.