Millie Bobby Brown is back as Eleven in a first look trailer from Stranger Things season 4. The release of the new video follows a tease from the prior day, with the Stranger Things YouTube account announcing that the Hawkins National Laboratory would be "back in service" on the morning of May 6th. Now online at the show's official YouTube account as well, you can watch the new sneak peek at Stranger Things 4 below.

In the clip, Dr. Martin Brenner (Matthew Modine) - whose face is never shown - is teased along with Millie Bobby Brown as Eleven. Seemingly set at the Hawkins National Laboratory run by Brenner where he helped raise and train Eleven, the footage culminates with a look at a door with the number 11 on the front. When Dr. Brenner asks, "Are you listening, Eleven?," we see a close-up of Brown opening her eyes.

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It's worth noting that Dr. Brenner was originally killed off in the first season, or at least that's what it seemed like at the time. It's been teased in subsequent seasons that he is still alive, and there's a chance he'll come back in Stranger Things 4. It's not clear if the new teaser is of a flashback set in the past, or if Eleven is looking for Dr. Brenner using her telekinetic abilities. Unfortunately, no release date was revealed in the trailer.

Stranger Things is created by Matt and Ross Duffer. Following a group of youths plagued by supernatural evil in the town of Hawkins, Indiana, the series premiered on Netflix in 2016 and became an instant hit with viewers. It stars Millie Bobby Brown, Gaten Matarazzo, Finn Wolfhard, Caleb McLaughlin, Noah Schnapp, Joe Keery, Charlie Heaton, Natalia Dyer, Sadie Sink, Dacre Montgomery, Winona Ryder, and David Harbour.

Previously, viewers were left with a cliffhanger ending at the end of season 3, which left the fate of Jim Hopper (David Harbour) unknown. Last year, Netflix released a teaser video revealing that Hopper is alive, but for reasons that have yet to be revealed, he's now being held captive in Russia. Hopper's return was one of very few details that had been revealed about Stranger Things 4, but the Duffer Brothers teased a "new horror" on the horizon when the teaser was released.

"We're excited to officially confirm that production on Stranger Things 4 is now underway - and even more excited to announce the return of Hopper," the Duffers said at the time. "Although it's not all good news for our 'American'; he is imprisoned far from home in the snowy wasteland of Kamchatka, where he will face dangers both human...and other. Meanwhile, back in the states, a new horror is beginning to surface, something long buried, something that connects everything..."

Back in January, Gaten Matarazzo also teased that season 4 would be the most frightening one yet. Speaking with US Weekly at the time, Matarazzo said "most would probably say it's the scariest [season] out of the previous three," adding that the scary stuff is "very fun to film." Despite the dark material, the young actor also said how the cast finds it pretty easy to keep things happy and upbeat on the set.

"We don't have to try too hard. We like each other, which is always a plus," Matarazzo said. "As well as having a lot of the heavy, dark stuff in the show, it's surrounded by a lot of lightheartedness [and] a good amount of comedy. ... We usually have a fun time on set."

Stranger Things season 4 doesn't yet have an official release date at Netflix. The new video comes to us from the official account for Stranger Things on YouTube.