Stranger Things has returned to Netflix for its second season - and it's great, garnering positive reviews and a very favorable fan reaction. With the threat of the Shadow Monster, and the Upside Down trying to worm its way into Hawkins, its residents once more banded together to extinguish the threat - with a lot of help from Eleven, of course.

As with all good TV shows, Stranger Things Season 2 has prompted widespread discussion and, while the nine-episode run was deeply satisfying, it also left us with a whole lot of questions. Let's try and tackle some of the biggest ones.

Eleven, The Upside Down and Hawkins Lab (This Page)

Is the Shadow Monster Going to Return?

At the end of Season 2, Eleven closed the gate, effectively meaning there is no way for the Upside Down to permeate Hawkins anymore. But we all know that doesn't mean it's gone for good. In a final shot, the Upside Down version of Hawkins Middle School had the Shadow Monster looming large above it, surely meaning its return is imminent.

Will we see the Shadow Monster being the main antagonist of Season 3, or are even bigger monsters on their way? Given the way the mythology has been expanded, it makes sense that the Shadow Monster will find some way back into Hawkins, and that this time, the threat will become even more deadly. The Mind Flayer now knows about Eleven and her powers, and the Duffer brothers themselves have pointed out that while the gate might be shut, the connection is still there:

"They've shut the door on the Mind Flayer, but not only is it still there in the Upside Down, it's very much aware of the kids, and particularly Eleven. It had not encountered her and her powers until that final episode. Now, it knows that she's out there."

Is Dr. Brenner Still Alive?

Stranger Things: Duffer Brothers Discuss Barb & Brenner's Fates

At the end of Season 1, we all assumed Brenner, or Papa, as Eleven calls him, was gone for good. After all, that final encounter with the Demogorgon looked pretty horrific. But during Season 2's controversial episode 7, Kali (Eight), summons him in a vision and forces Eleven to face her demons. Although Eleven insists he's dead, Kali thinks otherwise and accuses her "sister" of not looking for him on purpose.

So if Brenner is still alive, where is he, and what on earth is he up to now? Executive producer Shawn Levy recently confirmed that "Brenner is alive, Brenner is out there." Surely that means we can expect to see him in Season 3? The defining question then is who will confront him first, Eleven, or Eight?

Will Eight be back?

Given that an entire episode of the second season was given over to Eleven meeting her "sister", it seems likely that Eight (Linnea Berthelsen) will return. Not only does her character give further insight into what went on at Hawkins lab, as well as the world's telekinetics, Eight also serves as a tool to highlight how much Eleven values family and friendship above exacting revenge.

Jane uses her powers to save, Kali uses hers to harm. Two children who underwent the same experiments and upbringing (we assume) who took two very different paths. Nature vs Nurture at its finest, and it is worthy of more exploration, especially if the pair of them are reunited with Brenner. Where and how Eight might reappear in Eleven's life again remains to be seen, but given how strange it was going to Chicago, it would be interesting to see her arriving in Hawkins.

Where Are Experiments 001-007 and 009-010?

The two girl's names say it all; there must be more of them out there. Doubtless not all survived, but even so, it would be good, given the differences between Eight and Eleven, to see how at least some of the others have turned out. Are any of them male? Do some live 'normal' lives and not use their powers at all? Are some still being held in labs? Is Eleven the end of the line, or are there many more?

For this plot thread there are not many clues but, again, given how prominent Kali is in Season 2, it would be crazy to suggest we won't see more superpowered individuals at some point.

Will Byers in Stranger Things

Is Will Okay Now?

After two awful years, things are finally looking OK for Will Byers - and we really hope they stay that way. Noah Schnapp didn't really get much to do in Season 1, but the second year was his moment and he owned it, delivering a tremendous, varied performance. That said, Will is just a kid and it would be kind of nice to see him getting the chance to really be a part of the party in Season 3.

Whatever happens, it appears that the connection is broken, and he's no longer playing host to the Mind Flayer; even though the whole experience will stay with him, Will can return to being a regular teenager with his friends. For a little while at least.

Are Dustin and Hopper Infected?

Hopper spent a long time in that eerie network of tunnels under Hawkins until Joyce and Bob saved his life. During that time, he was sprayed in the face with some kind of goo, and after when he was in the lab, we saw him coughing up some kind of gross green substance. Then, during the season finale, Steve, Lucas, Max, Mike and Dustin all took to the tunnels as well, and Dustin was sprayed right in the mouth with the same substance.

Read More: Stranger Things: How Season 2 Sets Up Season 3

If you ask us, it seems too much time spent on a scene just to throw it away, and we're betting that there will be repercussions for both Dustin and Hopper in Season 3 owing to their contamination.

Will We Ever Fully Understand Hopper's Backstory?

Hopper during an investigation at the Byers house.

Poor Hopper has had a hard life, we realize that, but what exactly happened? We know he used to live in a city with his wife Diane, and together they had a daughter, Sara. Unfortunately, Sara had cancer and died at a young age, and the effect her death had on her parents meant that their marriage crumbled.

In Season 2, Hopper is a surrogate father caring for Eleven. The two share a turbulent relationship as Eleven tries to live as normal a life as possible, and Hopper tries to protect her. What is clear throughout the season, is how much the two care for each other; Hopper says he's scared of losing Eleven like he lost Sara - that he feels like he's a black hole where everything that he holds dear, ends up destroyed. The very end gives him a chance at redemption, with him officially made Jane's father.

For next season, it would be good if we could have Hopper's backstory explained in a little more detail. Where is Diane now, and will she ever come back? How could his failed marriage affect any future relationships? And, yes, we have our eye on Joyce Byers, of course; now that Hopper is officially a father to Eleven (or will he now call her Jane?), he's going to have to relax slightly and let the kid grow up in a loving and stable environment.

Will Eleven and Max be friends?

Sadie Sink made a great impression as Mad Max, the "totally tubular" teen with a crush on Lucas. However, not everyone was so smitten. Mike didn't take to Max at all at first, and he was outright enraged when Lucas told Max their backstory. His reaction was understandable - any girl coming into the group was bound to remind him of Eleven and open old wounds - but Jane also took an instant dislike to Max. Granted, Max dared to make Mike smile when Eleven was watching them, and she didn't like the thought of him being happy without her, but when Eleven returned and Max offered her hand, Eleven immediately blanked her and went to Joyce instead. Not only that, but when closing the gate, Eleven focused her anger and in that run of flashbacks, Max also featured.

Read More: Stranger Things: Who Are The New Cast in Season 2?

With Eleven now allowed back into Hawkins society (when Season 3 starts), the relationship between these two hotheaded young girls is sure to cause some fireworks.

What's The Real Deal With Billy and Max?

Stranger Things Fashion: The 5 Most Iconic Looks

Billy (Dacre Montgomery) swept into Hawkins and wasted no time establishing his place as a cruel bully who cared for no one. While Montgomery played the part well, the character was fairly one-dimensional for most of the series. We gathered that he hates Lucas, presumably out of ingrained racism, and we also learned that he drives like a maniac and has a penchant for ridiculously tight jeans. It was only towards the end of the season that we really got a decent look at his character's backstory, and it was all too brief.

Arrogantly strutting around getting ready for a date, Billy was unaware that Max had climbed out of her window. When his dad and stepmom discovered this, Billy was set upon by his dad, who is clearly both mentally and physically abusing his child. In the subsequent scene with Max at the Byers' home, it was abundantly clear that Billy is doing to her what's being done to him in an effort to make himself feel better.

Going forward, it'd be great to learn more about Billy and Max; how their relationship got so bad and why exactly they came to Hawkins. There's also the bigger dangling query about his intentions towards Mrs. Wheeler - and hers towards him.

Can Steve and Dustin Stay BFF's Forever?

Whoever first thought to pair Dustin and Steve together is, in no uncertain terms, a genius. Steve has done a complete 180 since Season 1, proving to be a kind, decent human being with a love of hair products. Meanwhile, Dustin is just awesome in all things. They make a brilliant team, and the fact that Steve not only helped Dustin with his hair styling but also gave him a ride to the Snow Ball is conclusive evidence that these two are BFF's and need to stay that way for life. Don't break our hearts, Duffers.

Next: How Long Will Stranger Things Last?

Stranger Things season 2 is available for streaming on Netflix now.