Spoliers Ahead. Walk away if you haven't seen Episode 5 yet. 

Disney's WandaVision might have gotten off to a soft start but the show has since gotten better with every episode. Each episode just gives a little bit of the story away and as of right now, it has not only piqued viewers' interest but has also opened the doors for countless new characters. So naturally, every episode is awaited with countless fan theories. To make it easier for you, we just chose the ones that could really really happen. 

1. The neighbour Agnes is actually the old witch, Agatha Harkness from Marvel Comics. 

It would make sense too. She seems to be one of Wanda's closest friends and has a general idea of what's going on in Westview. And unlike the other residents, S.W.O.R.D hasn't been able to identify her yet. In the comics, she was a mentor to Wanda and later became a primary antagonist in her stories. 

Source: Comicbook

2. Wanda's children, Tommy and Billy are actually Mephisto's creation.

In the comics, Wanda uses magic from Mephisto to create children; magic that absolves later, killing the boys. Besides, Darcy Lewis made it clear that the boys were not previously present at Westview, and Wanda doesn't seem to have any control over them. She couldn't stop them from ageing or making them stop crying. 

Source: Radio Times

3. Speaking of Mephisto, Wanda might not entirely be in control of Westview. 

While episode 4 made pretty clear that Wanda knew and was in control of whatever was happening, episode 5 crept in with some doubts of its own. When Vision asks Wanda if she knew she was hurting people, she seemed to have no answer. She also has no recollection of how it all started. It could be possible that Mephisto could be behind Westview and Wanda may have made some deal with him, which is why she was so adamant about never leaving town. 

Source: Cheat Sheet

4. Pietro's return could mean the beginning of MCU's multiverse. 

The biggest question after the last episode was how the hell was Quicksilver from the X-Men playing MCU's Quicksilver! Besides, MCU's Pietro is dead. And this is something that Wanda did not control. She didn't even recognise him at first. It'll be interesting to see how they explain this crossover but this definitely makes the X-Men officially cannon. Perhaps Wanda and whatever else is involved there has tapped into parallel universes. 

Source: Decider

5. Monica Rambeau already has her powers. 

This would explain her getting uncomfortable when Darcy and Jimmy started talking about Captain Marvel. In episode 5, when she wakes up on the S.W.O.R.D. base, we find that her lab results are mysteriously blank. The medic requests another blood draw, and Monica straight-up refuses.

In the comics, Monica had gone by multiple aliases, including Photon, Spectrum, Pulsar, and Captain Marvel. In fact, Photon is her nickname on the show. She even tells Darcy to prepare a '10,000-pound fallout shelter comprised of lead for photons'.Wonder, she plans on unleashing her powers. 

Source: MCU Wiki

6. The people in the WandaVision commercials are people Wanda knew in real life, including her parents. 

All the ads have different couple sell different products- from Hydra Soak to Lagos paper towels. One would assume that these are part of Wanda's memory and could actually feature real people she knew relative to that phase of her life. Her parents died when terrorists attacked with Stark Industries' missiles. So the people in the Stark Industries toaster could very well be her parents. 

Source: Elle

7. S.W.O.R.D might be the bad guys. 

MCU does have the habit of turning corporate into the bad guys. It's done so before with SHIELD and HYDRA. When we Wanda storming their facility to rescue Vision, his body seemed to have been dismantled, possibly being experimented with. Besides, Director Hayward has the same energy as Alexander Pierce!

Source: Looper

8. The original missing person in the missing person case that led to this whole investigation could be Mephisto. 

Monica and Jimmy first showed up in Westview because of a missing person case. This guy is a male in a Witness Protection Programme. So there is nothing known about him. Earlier in an interview, actor Paul Bettany had said: 

So many things get leaked, but there’s this thing that has been completely under wrap that happens. I work with this actor that I’ve always wanted to work with and we have fireworks together—the scenes are great and I think people are going to be really excited. I’ve always wanted to work with this guy and the scenes are pretty intense.

Now, pretty much all important characters have been introduced. Actually the only one we always keep hearing about but never actually seen is Agnes' husband Ralph. Some argue that Ralph is Mephisto. 

Source: Variety

9. Billy and Tommy are the only children in Westview for a reason and it could be leading towards a Young Avengers storyline. 

Billy and Tommy Maximoff, aka Wiccan and Speed, have the abilities of both Wanda and Pietro and in the comics, they go on to become the leaders of the Young Avengers. And in the show, it doesn't look like she can control them. So, could it be that that's the reason there are no kids in Westview? There are too many possibilities here so it's futile to speculate but the twins being the only kids in Westview must play an important role in the story. 

Source: Screen Rant

10. Vision is back for good. 

The chances of Vision surviving seem more and more but it seems unlikely that they would bring back a character who had such an impactful death in Infinity War, just to kill him on a sitcom. He might just die again, make no mistake, but it doesn't mean that he stays that way for long. He's a machine, after all. 

Source: Comicbook

What started off as a weird black and white sitcom has somehow turned out to be one of the more unique things MCU has recently done. Each episode is better than the last and it would appear that you'll need to watch the show to make sense of the MCU movies to follow!