'Stranger Things': Is Hopper alive? Did Eleven lose her powers? What to know before Season 4

At long last, "Stranger Things" fans are about to return to Hawkins, Indiana – and hopefully, get answers to some long-awaited questions.

Why is Hopper in Russia? Did Eleven really lose her powers? ... And where exactly did the show leave off again?

It's been almost three years since Season 3 debuted on Netflix, which is plenty of time for even the most diehard fans to forget some important details. The new season, arriving Friday, picks up six months after Season 3, with the group of friends separated for the first time and "navigating the complexities of high school." (Seven episodes will be released, with two more due on July 1).; the first eight minutes of the season are here.) 

To jog your memory before the new season drops, here are the biggest cliffhangers and questions from Season 3.

'Stranger Things' Season 4 trailer is full of surprises: What to know about penultimate season

Police Chief Jim Hopper (David Harbour) and Joyce Beyers (Winona Ryder) in "Stranger Things"

What the heck happened to Hopper?

During the Season 3 finale, Police Chief Jim Hopper (David Harbour) and Joyce Byers (Winona Ryder) go undercover as Russian officers to infiltrate a secret Soviet base underneath the Starcourt Mall.

Hopper and Beyers successfully destroy the laser the Soviets operated to keep open a portal to the Upside Down, thus destroying The Mind Flayer monster the kids are battling upstairs.

But it comes at a cost: Joyce hits the switch, causing the laser to explode with Hopper standing right beside it. She runs to the other side of the glass after the explosion, but Hopper is nowhere to be found – and he's presumed dead by Joyce and the kids. A newspaper headline reads: "Hero chief dies in fire."

'Stranger Things' teases the return of David Harbour's Hopper in Season 4

Or did he?

A post-credit scene of Russian guards picking out a prisoner had fans abuzz. The guards stop at a closed cell, but one of the guards says, "No, not the American," and they choose a different prisoner instead to feed to a Demogorgon downstairs. Was Hopper "the American"?

The first teaser trailer for Season 4 seemed to say so.

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The 50-second clip, released in February 2020 and titled "From Russia with love…," zoomed in on a snowy work camp with barking dogs and armed guards. One of the workers? None other than Hopper.

"He is imprisoned far from home in the snowy wasteland of Kamchatka, where he will face dangers both human ... and other," the show's producers Matt and Ross Duffer, known as the Duffer Brothers, said of Hopper at the time. "Meanwhile, back in the states, a new horror is beginning to surface, something long buried, something that connects everything."

Finn Wolfhard as Mike Wheeler and Millie Bobby Brown as Eleven in the fourth season of "Stranger Things"

Eleven and the Byers bid farewell to Hawkins

But Eleven (Millie Bobby Brown), whom Hopper adopted and treated like a daughter, doesn't know he's still alive.

The Season 3 finale ended with her tearfully reading a touching speech Hopper had written for her but never had the courage to share. After finishing the letter, she bids goodbye to her friends before getting in a car and driving off with the Byers family, moving somewhere new.

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Where are they off to? A teaser trailer released in November, titled "Welcome to California," that shows Eleven navigating a new school, may hold the answer.

Eleven (Millie Bobby Brown) and the kids of "Stranger Things" took on The Mind Flayer in Season 3.

Will Eleven get her powers back?

Eleven has another problem: the supposed loss of her powers after the battle with The Mind Flayer.

Her friend-turned-romantic-interest Mike Wheeler (Finn Wolfhard) assures her the loss is only temporary, after Eleven unsuccessfully tries to grab something using her telekinesis while packing.

Is Eleven just going through a slump? Or is her superpower really gone for good?

'Stranger Things' Season 4 trailer is full of surprises: What to know about penultimate season

Art for Season 4 of "Stranger Things."

Season 4 is the 'beginning of the end'

In a letter to fans Feb. 17, the Duffer Brothers said the fourth season will mark "the beginning of the end" of the beloved series.

"Seven years ago, we planned out the complete story arc for 'Stranger Things,'" they wrote. "It proved too large to tell in four (seasons) – but, as you'll soon see for yourselves – we are now hurtling toward our finale. Season 4 will be the penultimate season; season 5 will be the last."

But don't worry, "Stranger Things" fans. The Duffer Brothers assured there are "still many more exciting stories" to come before the show ends, including new mysteries, adventures and characters.

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