Stranger Things releases new trailer for season 4: 'Eleven, are you listening?'

Listen up Stranger Things fans, this is not a drill! Netflix has released a surprise, chilling new trailer for season 4 of Stranger Things that seemingly throws it back, all the way to season one.

In the cryptic clip, unveiled on Thursday (May 6), we see a group of young children dressed in medical robes, with shaved heads, playing in a room that eerily resembles the 'medical' facility that Eleven escaped from in season one.

Halfway through the clip, we watch a faceless figure walk into the room and tells them: "Good morning, children," to which they creepily reply: "Good morning, Papa." Tension builds as the camera turns and zooms in on a door with the number "11" on it, and the mysterious figure declares: "Today, I have something very special planned for you."

The screen goes dark, and we hear the man once more: "Eleven, are you listening?" - before the tailer cuts to a shot of Eleven's eyes opening.

See Netflix's Stranger Things season 4 trailer below

Stranger Things' Millie Bobby Brown has been keeping fans engaged on social media amid the delay of season 4. She posted several sexy selfies on her Instagram page - click here to see!