'Stranger Things' season four: what we've learnt from the eerie new teaser trailer

We finally know when it'll be released ...

'Stranger Things' season four seemingly delves into Eleven's dark past. Netflix

The much-awaited season four of the hit Netflix show Stranger Things will return in 2022, the streaming service confirmed in a new teaser trailer released on Friday.

Although season three ended in 2019, the series has been heavily delayed because of the pandemic. While the new teaser trailer doesn't really offer anything new, it has got fans excited. Since it was released on YouTube, it has been viewed more than three million times.

What we've learnt from past trailers

In May, Netflix released a teaser trailer for the coming season, which gained more than two million views within 24 hours.

Running at just over a minute, the trailer appears to take place in a medical facility and season one antagonist Dr Martin Brenner seems to make an appearance.

It's three o'clock (whether it's night or day remains to be seen) and children in medical gowns are playing games together.

A Magic 8-Ball ominously reads: "Signs point to yes."

A shadowy grown-up figure, who looks suspiciously like Brenner, walks towards a door. "Good morning, children," he calls.

"Good morning, Papa," they reply in unison, using the moniker commonly given to Brenner in past seasons, as eerie music plays in the background.

"Today, I have something very special planned for you," the man continues, as the focus pans to a door with the number 11 on it and the sound of heavy breathing intensifies.

"Eleven, are you listening?" asks a voice, as the character Eleven (Millie Bobby Brown) suddenly opens her eyes.

It does not tell us anything concrete, but it appears to be a flashback and season four may offer us more of a glimpse into the young girl's dark past at Hawkins National Laboratory.

In February 2020, another trailer titled From Russia with love ... was released and confirmed Hawkins police chief Jim Hopper, who seemed to have been obliterated by a Russian laser at the end of season three, is actually still alive (as if we didn't know that already).

In the clip, Hopper is hammering away at a snowy train line with what appears to be a group of prisoners.

While some may have assumed this would be the final instalment of the hit sci-fi show, in August, co-creator Ross Duffer told The Hollywood Reporter that "season four won't be the end".

"We know what the end is, and we know when it is," he said of the storyline. "The pandemic has given us time to look ahead, figure out what is best for the show. Starting to fill that out gave us a better idea of how long we need to tell that story."