Ironically, outside of the Marvel Cinematic Universe’s Captain America trilogy, villainous organization Hydra factored most prominently into Agents of S.H.I.E.L.D. and Agent Carter, two shows that are no longer considered official canon within the franchise.
The shadowy outfit were referenced in both WandaVision and The Falcon and the Winter Soldier, although they didn’t weigh too heavily on the plot in a direct manner, but we’re hearing from our sources – the same ones who told us the project was in development long before it was confirmed – that Sam Wilson’s solo debut under the star-spangled costume will be exploring Hydra’s history.
While it would arguably be a much better and wiser idea for Captain America 4 to distance itself away from the Steve Rogers mythology to let Sam stand on his own two feet, Hydra are intrinsically linked to the entire history of the moniker dating back to World War II and their attempts to replicate the initial super soldier serum, which resulted in Johann Schmidt’s Red Skull.
From there, they infiltrated every level of the U.S. government to establish a covert iron grip on global society, leading to their involvement in the assassinations of Howard and Maria Stark, the entire Winter Soldier program and even the imprisonment of and experimentation on Isaiah Bradley if you think about it.
There’s no word yet on how these plot machinations will reveal themselves, but it could set the stage for some flashbacks tying the overarching Captain America series together as one coherent story that began with Steve Rogers and Red Skull, lasting decades upon decades right through to the potentially antagonistic presence of Contessa Valentina Allegra de la Fontaine, also known as Madame Hydra in the comic books.