The Road to Doomsday Part 3 — Captain America: The First Avenger (2011)

From the first look at an Infinity Stone to the introduction of three vital characters for the MCU’s plotline, Captain America: The First Avenger is definitely necessary for the comprehension of the entire MCU and, therefore, Avengers: Doomsday. The film’s opening scene shows the Space Stone inside the Tesseract, an object that will later unite the plotline of various films into The Avengers (2012). 

MCU: The Road To Doomsday:

• The AVENGERS: DOOMSDAY Trailer is Out, and It’s Everything We Could Hope For!
• Avengers: Doomsday Trailer, X-Men Cast Announcement, VisionQuest Trailer and more! — Everything that happened for Marvel during D23
• The Road to Doomsday Part 1 — X-Men (2000)
• The Road to Doomsday Part 2 — X2 (2003)

Captain America: The First Avenger introduces the audience to Steve Rogers, an altruistic military scrawny outcast that turns into America’s first superhero after being injected with the super serum. Ultimately, this film is the reason why reading “Steve Rogers will return in Avengers: Doomsday” last December felt so personal — because we got to see his character development from the start. We got to see a tiny, fragile Steve promising that he could fight someone much bigger than himself all day, which lays the groundwork for the determinate, compassionate character we followed passionately until he lifted the Mjolnir. His determination and will to take on battles by himself is exactly what makes him the ‘miracle’ Thor called for in the Avengers: Doomsday trailer. 

The film also introduces Peggy Carter and Bucky Barnes. Peggy Carter is much more than Steve’s love interest, she became a crucial character for the MCU plotline and beyond (even starring in her own television series at one point). Apart from appearing in the Captain America trilogy, she was also featured as her famous variant Captain Carter in Doctor Strange: Multiverse of Madness. She also symbolizes the life Rogers should have had, which he went back for in the end of Avengers: Endgame. 

Bucky Barnes is Rogers’ best friend and trusted partner, who tragically falls off a train in the middle of the film — later to be captured and mind controlled by Hydra. Since then, finding and rescuing Bucky became a central arc in the Captain America trilogy. Steve successfully rescues him and, a decade later, Bucky becomes the leader of the Thunderbolts (we’ll get on that in about 10 weeks) and one of the leaders of the Avengers that will stand up against Doom. 

Other major characters and plot points are introduced here too. Hugo Weaving takes on the form of Red Skull, a Hydra leader that aims to use the Infinity Stone for Earth domination. The character appears again in Avengers: Infinity War and Endgame, as the keeper for the Soul Stone. 

The film is set in the Second World War, but ends with both Steve and Bucky undergoing circumstances that slows their aging process. Peggy, on the other hand, ages normally and the version that will return in Avengers: Doomsday is either a variant (maybe even Captain Carter) or herself from the past.