The illusion that messed with all our heads in 2018 has made a revival to wreak havoc once again.
We all remember the mind-boggling clip of a futuristic voice saying either 'Brainstorm' or 'Green Needle' depending on which of the words you read to yourself as they appeared on screen.
It was one of many viral illusions (think back to The Dress) which took over the internet many moons ago.
The original sound first appeared on YouTube account Check It Out.
But prepare to lose your marbles all over again, as the clip is back and causing as much of a stir among punters as it did the first time around.
It recently appeared on a Tik Tok with the caption: 'You will only hear the word you're reading'.
One Twitter user wrote: "OMG - mind blown!!"
While another penned: "That’s astounding."
And a third added: "What kind of sorcery is this?"
In 2018, a representative from Check It Out said: "If you think of either word, you hear it!
"If you have trouble hearing the other word, just pause the video, get the other word in your head and you will hear it when you click play.
"This is trickery of the mind.
"You might have to work at it to hear the other word."
There have been many viral videos online that have messed with our heads over the years.
Social media was sent into meltdown when a soundbite appeared on Reddit of a computer-generated voice saying either "Yanny" or Laurel" depending on how your ears pick up frequencies.
