'Avengers 4': Best Theories on What the Russo Brothers' Mystery Photo Is

Avengers 4 is still shrouded in quite a lot of mystery, and the latest tease from the film's directors is making fans get pretty creative.

Earlier this week, the Twitter account for Joe and Anthony Russo tweeted a photo of a mysterious lit up object, with a caption that seemed to indicate that they have wrapped on Avengers 4. In the days since the photo was posted, fans have debated and speculated about what the photo could be, with no real consensus yet.

Still, that hasn't stopped the Internet from coming up with its fair share of fan theories, which range from the relatively possible to the ones that are somewhat of a stretch. Here are just a few of our favorites.