Marvel is not known for subtlety but it is good at keeping a secret or two.
Despite leaked set photos and wild speculations, any salient details about the Avengers 4 plot have largely gone unsubstantiated.
Even Avengers 4 title remains a mystery, with names being bandied about on Reddit without a sliver of confirmation.
Will Doctor Doom villain appear in Avengers 4?
Victor Von Doom, aka Doctor Doom, has been one of Marvel's most ubiquitous villains.
Decades worth of comics have seen Doom going up against the Fantastic Four.
However, Doctor Victor Von Doom has also tormented the Avengers, Spider-Man, and plenty of other Marvel superheroes in his tenure as a villain in the Marvel universe.
For casual movie fans who may not know Doom's backstory, he is the son of a Romani witch and ruler of the nation of Latveria.
He is a master of science and magic and, though merely mortal, has in the comics more than once made his way to the status of a god.
Doom's particular brand of megalomania would make him an interesting villain in comparison to Thanos.
Thanos' motivation seemed to stem from some underlying desire to do good (as warped as the actions he took were).
Unfortunately for Doom, his portrayal on the big screen has always been somewhat lacking.
That could all change now.
Doctor Doom's rights had belonged to Twentieth Century Fox but now with the Disney-Fox deal, the issue of who owns Doom is no longer.
Kevin Feige reportedly had designs to cross-pollinate the X-Men and other Fox-owned comic characters with the Marvel Cinematic Universe.
While nothing has been confirmed as far as an X-Men or Fantastic Four crossover into the MCU, fans have reasons to be hopeful.
CBR.com thinks Doom too powerful of a villain to be introduced to Avengers 4 without it becoming muddled at best.
Over-crowding is a cornerstone of the Infinity War plot so the likelihood of further crowding by adding another megalomaniac to the cast seems somehow unlikely.
But, as we've seen with Marvel before, nothing is truly off the table.
Avengers 4 is in cinemas April 26, 2019.