The simple story titled Lights Out starts with a girl turning off her light to go to bed - but then it quickly escalates into something seriously unsettling.
Directed by award-winning short film maker David F Sandberg, the dialogue-free short caused a LOT of people to leave the lights on when they saw it for the first time last year.
And, now that it's resurfaced, it is stirring up emotions (and stomachs) all over again.
It starts with a girl, played by actress Lotta Losten, in a pyjama top flicking off the light in her hallway. A simple little everyday action that we all do - but, for her, it has terrifying consequences.
Because, with seemingly nobody else in the flat, we suddenly spot a silhouette… and it's clear that something is afoot.
Check it out for yourself below - if you dare.
Were you, like Twitter users everywhere, left seriously freaked out by this mini horror movie?
Let us know in the Comments Box below, stat!