Stranger Things season 3 left some major unanswered questions following the evil Mind Flayer's latest attack on the town of Hawkins, Indiana. Once more, the young heroes, including Eleven (Millie Bobby Brown), Mike (Finn Wolfhard), Lucas (Caleb McLaughlin), Max (Sadie Sink), and Will (Noah Schnapp), took on the beast from the Upside Down but the conclusion of Stranger Things season 3 upended the status quo as Billy Hargrove (Dacre Montgomery) and Sheriff Jim Hopper (David Harbour) both apparently died.

Set in early July 1985, Stranger Things season 3 revolved around the Mind Flayer taking over several of Hawkins' townspeople, starting with Billy, in order to kill Eleven. Concurrently, the new Starcourt Mall became the focal point of the town until Dustin (Galen Matarazzo), Steve (Joe Keery), Robin (Maya Hawke), and Erica (Priah Ferguson) discovered the mall was actually a front for a secret underground Russian base where the Soviet Union was trying to breach the Upside Down using their own Key. By the final episodes, all of the storylines converged so that Nancy (Natalia Dyer), Jonathan (Charlie Heaton), Hopper, Murray (Brett Gelman), and Joyce (Winona Ryder) all joined forces in the Stranger Things season 3 finale, "The Battle of Starcourt."

RELATED: Stranger Things Season 3's Ending Irreversibly Changes The Show

Generally praised as an improvement over Stranger Things season 2 and a return to form for the series, Stranger Things season 3 has set Netflix streaming records, introduced a new fan-favorite character in Robin, expanded the scope of its universe, and set the stage for the story to continue in Stranger Things season 4. However, the series also doubled down on product-placement and nostalgia for 1980s music and movies, recycled many of its tropes and, once again, the villains' motivations were sketchy and unclear major plot threads were left unresolved. All in all, here are our biggest questions about Stranger Things season 3.

12. Is Hopper Really Dead?

Jim Hopper Death In Stranger Things Season 3

Whether Jim Hopper really did die when the Russian Key to the Upside Down exploded is the biggest question coming out of Stranger Things season 3. The poor sheriff never got his date with Joyce Byers and his sacrifice left Eleven without the man she's come to regard as her father. Even before he died in the Russian base, Hopper suffered through a difficult season where he fought a Terminator-like Russian assassin and suffered serious beatings, not to mention his shack in the woods was destroyed by the Mind Flayer.

Since Hopper's body wasn't found (even though it was specified the Key would vaporize him), the possibility exists the scruffy lawman did survive and could reappear in Stranger Things season 4 - which is strongly teased if fans call the phone number of Murray Bauman and hear his voice message suggesting Hopper could still be alive. (David Harbour's contract also includes an option to return for Stranger Things season 4.)

11. Who Is The American Imprisoned By The Russians?

Stranger Things season 3's climactic moments take place at a Soviet prison facility in Kamchatka, USSR. A doomed Russian prisoner is dragged into a face-to-face confrontation with a Demogorgon but the truly compelling part is right before when an unknown American prisoner is spared that fate. Who could "the American" be? The most obvious possibility would be Jim Hopper, who the Red Army would have captured as they evacuated their Starcourt Mall base before the U.S. Military arrived.

Related: Stranger Things: Is Sheriff Hopper Really Dead? Here's How He Could Have Survived

10. Where Is Dr. Martin Brenner?

Stranger Things Eleven and Dr Brenner In Lab

Another possibility for the prisoner in Kamchatka could be Dr. Martin Brenner (Matthew Modine). Brenner, the scientist who "created" Eleven, was presumably killed by the Demogorgon in Stranger Things season 1. However, his fate was never confirmed and Brenner could still return in Stranger Things season 4. It's not clear how the Russians could have captured and imprisoned Brenner halfway around the world but they have a motive: In Stranger Things season 1, episode 5 "The Flea and the Acrobat", a flashback showed Brenner making Eleven use her powers to spy on the Soviet Union. This moment was the first tease of the Russians' future involvement in Stranger Things season 3; it's possible the USSR realized what Brenner was up to and capturing the white-haired scientist led to the Soviet Union's own interest in breaching the Upside Down.

9. How Did The Russians Capture a Demogorgon?

Demogorgon in Stranger Things

Stranger Things season 3 makes the Russians a real threat. The season began with the Soviet Union failing to open a gate to the Upside Down, which led to the construction of the Key beneath the Starcourt Mall one year later. But apparently, the Russians did have success reaching the Upside Down during that year because they captured a Demogorgon. The fact the USSR has one of the deadly creatures makes them more successful than the Americans, who have apparently not managed to snag one of their own (although the Soviet Union has no Eleven of their own to kill the monsters). But the hows and whys of the Russians possessing a Demogorgon remain a mystery that will hopefully be answered in Stranger Things season 4.

8. Do The Russians Have Any Other Monsters From The Upside Down?

Stranger Things 3 Trailer - Upside-Down Monster

The return of the Stranger Things season 1 Demogorgon begs the question of whether the Russians have encountered other creatures from the Upside Down, perhaps even new monsters the residents of Hawkins, Indiana haven't faced yet. At the very least, do the Soviets only have one Demogorgon or do they have more - and how did they manage to capture it? What's more, have any Russians encountered the Mind Flayer and does the ruler of the Upside Down have any agents under its thrall in the USSR?

7. How Did The Russians Build A Secret Base Beneath Starcourt Mall?

Dustin Robin Erica and Steve in Stranger Things Season 3

The U.S. Military was a non-factor until the very end of Stranger Things season 3 and they completely missed the massive national security threat in Hawkins, Indiana, i.e. the Soviet Union was able to construct a massive underground base on U.S. soil and build Starcourt Mall above it. But even with Mayor Kline (Cary Elwes) looking the other way and taking kickbacks to the detriment of Hawkins' downtown businesses, how did the Russians build that entire base in one year and staff it with Red Army soldiers all completely under the nose of the United States? And are there any other secret Soviet installations beneath malls elsewhere in the U.S.?

RELATED: Stranger Things Complete Timeline Explained

6. How Did Eleven Lose Her Powers And Can She Get Them Back?

Stranger Things Season 3 Mind Flayer and Eleven

Eleven's leg was infected by a piece of the Mind Flayer's Meat Monster at Hopper's cabin but after a grotesque and painful surgical attempt by Jonathan, El used her telekinesis to tear the creature from her body. However, Eleven lost her powers afterwards. It's unclear whether the sheer strain of removing the monster from her leg short-circuited El's psychic abilities or whether it's a side effect of the Mind Flayer infecting her body, but her powers still hadn't returned at the end of Stranger Things season 3. While this could be a welcome break for Eleven and a chance to feel normal, it's not clear if her telekinesis will manifest again or how it can happen in Stranger Things season 4.

5. Will Eleven's "Sister" Return In Stranger Things Season 4?

One way Eleven could get her powers back is by encountering her older "sister" Kali Prasad aka Eight (Linnea Berthelsen). El, whose real name is Jane Ives, met Kali in the infamous Stranger Things season 2 episode "The Lost Sister". While Eleven was tempted to remain with Kali, she rejected the vengeful life on the run Kali and her friends lived and chose to save her friends in Hawkins. However, Eleven moving away from the Indiana town with the Byers family opens up the chance of bringing back Kali. Eight's psychic powers differ from El's; Kali can project incredibly realistic illusions - could another meetup with her lost sister be the key to Eleven regaining her abilities?

4. Why Didn't The Mind Flayer Kill Eleven When It had Many Chances To?

Eleven and the Mind Flayer in Stranger Things

The Mind Flayer's whole goal in Stranger Things season 3 was to kill Eleven; it called the many people in Hawkins in its thrall to it and melted them to create a giant monster before attacking Eleven and the rest of the kids. However, Eleven hurt the Mind Flayer when she telekinetically exploded its head, allowing the young heroes to escape. But at "The Battle of Starcourt", the Mind Flayer still couldn't kill El despite her losing her abilities and the fact that it already wounded and infected her leg. Considering the Mind Flayer's actions in Stranger Things season 3 were so it could become powerful enough to kill Eleven, the fact that it failed so spectacularly really undercut a lot of its menace.

3. Why Did Everyone At The End Act Like The Mind Flayer Is Defeated?

For the third time, the heroic citizens of Hawkins sealed the Gate to the Upside Down and saved their town - temporarily. But by now, they should all know the Mind Flayer will return. In fact, earlier in Stranger Things season 3, they did know this because of the kids having the important discussion acknowledging it's not enough to seal the Gate, they have to eliminate the Mind Flayer from Earth entirely. Instead, Stranger Things season 3 ends with the Gate being sealed but the Mind Flayer still an enemy that will surely return in the future. However, after the emotional traumas of Billy and Hopper's death and the calamity at Starcourt Mall, plus the Byers and Eleven moving away, everyone seemed content they won - even though they all must know it isn't really over.

RELATED: How Old Are The Kids In Stranger Things 3?

2. Where Are The Byers And Eleven Moving To?

The Byers adopting Eleven and moving away from Hawkins is a smart move. Joyce's store in downtown Hawkins went out of business thanks to Starcourt Mall, Jonathan lost his job at the newspaper, and with Hopper dead, Eleven needed a fresh start away from Mike and the monsters in Hawkins. Even before they parted ways, Mike, Lucas, Dustin, Max, and Nancy made their plans to see the Byers and Eleven over the holidays but Joyce and her family never said where they were moving to. But maybe the Byers purposely didn't reveal their destination; if so, this would be a smart move. Getting as far away from Hawkins as they can but also not revealing where they're going would be an ideal way for the Byers to get a fresh start and keep Eleven safe.

1. Will Stranger Things Be Different In Season 4?

Stranger Things Season 4

Stranger Things season 3 has been warmly received by critics and fans, with some calling it the best season so far. However, it's also clear Stranger Things needs to change and could benefit from a shakeup of its worn-out formula of monsters breaching from another dimension, terrorizing Hawkins, and a handful of children fighting back. Meanwhile, the villains remain one-dimensional, with unclear motivations, and the resolutions to the problem of the Mind Slayer come off as stopgap solutions.

Stranger Things season 3 broadening the scope to include the Soviet Union's efforts to reach the Upside Down is intriguing and nicely ties into the waning days of the Cold War in the mid-1980s, but the series has also gone overboard with 1980's nostalgia and incessant product placement. While the kids, the town of Hawkins, and the period setting are the hallmarks of the show and the key reasons for its success, fans still hope Stranger Things season 4 can find a way to freshen up the series and not just repeat a variation of what they've done to death.

NEXT: What To Expect From Stranger Things Season 4

Stranger Things is available to stream exclusively on Netflix.