The sudden appearance of a cryptic symbol has added credence to one compelling theory about "Avengers: Doomsday."

Avengers: Doomsday director Joe and Anthony Russo have once again posted a mysterious tease to social media, but what are they hinting at ahead of the trailer's release?

Joe Russo and Anthony Russo have posted a new image on Instagram that ties directly to the upcoming Marvel film Avengers Doomsday. The picture shows an abstract