Captain America 4 is still more than a year away, but many rumors from legitimate sources have already spoiled certain parts of its story. The Falcon and the Winter Soldier writer Malcolm Spellman also wrote New World Order, and Julius Onah was later chosen to direct the film.Sam Wilson will continue his story as Captain America after he took on the mantle in The Falcon and the Winter Soldier. He is still new to the gig, so viewers will see him try to fill those big boots that Steve Rogers left vacant as a new conspiracy involving the Super Soldier Serum comes to the forefront.The film has begun production, and the set photos have revealed a few surprising characters that will appear in the film. Along with the characters, many plot details through rumors and scoops have surfaced online. As such, the following list reveals everything known about Captain America: New World Order so far.Disclaimer: This article contains potential spoilers for the plot of Captain America 4.Captain America 4’s cast and rumors1. Every rumored and confirmed character to appearCaptain America 4 cast at D23 Expo 2022 (Image via Disney)At D23, Kevin Feige revealed that besides Anthony Mackie’s Sam Wilson, Captain America 4 will have Carl Lumbly as Isaiah Bradley, Danny Ramirez as Joaquin Torres, and Tim Blake Nelson as Samuel Sterns, aka The Leader. It was later revealed that Xosha Roquemore will play Sam’s love interest Leila Taylor, and she will be joined by an Israeli superhero Sabra, played by Shira Haas.Harrison Ford will replace William Hurt as Thaddeus Ross. Other returning actors/characters include Liv Tyler as Betty Ross and Julia Louis-Dreyfus as CIA Director Val. Additionally, Sebastian Stan’s Bucky is rumored to get a cameo that sets up Thunderbolts.2. Who is Sabra?Shira Haas as Sabra (Image via Marvel)As mentioned above, Ruth Bat-Seraph, aka Sabra, is played by Shira Haas. She was also seen in the set photos involving a mystery funeral. In the comics, she is a mutant whose powers include superhuman strength, stamina, speed, and durability, along with enhanced reflexes and agility.Apart from that, she is also able to help others heal by transferring a portion of her "life energy" into them. It’s the opposite of what Rogue does, as fans have seen Rogue absorbing the life energy and power of other beings. However, Sabra gives her own life force to others. It would be interesting to see if she would carry the same ability within the MCU as well.3. President Ross recruits Samuel SternsMarvel Updates@marvel_updat3sIn #CaptainAmericaNewWorldOrder President Ross recruits The Leader to create the super soldier serum for the government. Captain America tries to unmask him, helped by Leila Taylor and Joaquin Torres#MarvelStudios2846265In #CaptainAmericaNewWorldOrder President Ross recruits The Leader to create the super soldier serum for the government. Captain America tries to unmask him, helped by Leila Taylor and Joaquin Torres#MarvelStudios https://t.co/AW7vhWnAjTAccording to the Twitter account of Marvel Updates, Thaddeus Ross still wants to recreate the Super Soldier serum. He will become President of the US after President Ritson dies in Secret Invasion. Then, he would bring Samuel Sterns back into the picture to recreate the serum. Hence, it’s possible that The Leader would be responsible for turning Ross into the Red Hulk.The whole mystery of Captain America 4 will be to unravel this truth of recreating the Super Soldier Serum. Sam will also be tempted to use it upon himself. However, he will fight the temptation and prove that Steve Rogers was right to choose him.4. Sam forms a new teamDivinity Seeker@DivinitySeeker1Captain America: New World Order is not an Avengers movie or about the formation of one, it’s a movie that is very much focused on Sam who tries to take on the world alone fighting the temptation of the super soldier serum as every villain goes against him and all his friends die twitter.com/DivinitySeeker…Divinity Seeker@DivinitySeeker1And one more tea… Sam Wilson’s #CaptainAmerica is NOT part of this Avengers team, and he won’t be forming any #Avengers team in his solo movie New World Order either. He is however forming A team, but they are all killed off at the end of his movie & Sam is off the grid 20120And one more tea… Sam Wilson’s #CaptainAmerica is NOT part of this Avengers team, and he won’t be forming any #Avengers team in his solo movie New World Order either. He is however forming A team, but they are all killed off at the end of his movie & Sam is off the grid ❌Captain America: New World Order is not an Avengers movie or about the formation of one, it’s a movie that is very much focused on Sam who tries to take on the world alone fighting the temptation of the super soldier serum as every villain goes against him and all his friends die twitter.com/DivinitySeeker…Most people believe that Sam will form the New Avengers team by the end of the film. However, that may not be the case. Instead, viewers may see him form a new squad that includes Joaquin Torres as the new Falcon. Back in The Falcon and the Winter Soldier, Sam gave his wings to Joaquin Torres. So, that setup may finally pay off when Torres becomes his sidekick.Along with him, fans would also see Sam’s love interest, Leila Taylor, who appeared in a recent batch of funeral set photos alongside Sam Wilson. Together, Leila and Joaquin will help Sam on his missions. However, as reported by scooper Divinity Seeker, one or both of them might die.While one part of the plot will be about Super Soldier Serum and Hulk-related characters, the other subplot will be about Adamantium.5. Tiamut Island and AdamantiumTiamut Island from Eternals (Image via Marvel)It is a long-running rumor that MCU’s supply of Adamantium will come from Eternals’ dead celestial, Tiamut. It has turned into a territory that’s up for grabs. While Wakanda keeps its Vibranium hidden, all countries in the world will fight to get their hands on Adamantium.It will eventually lead to the Weapon X program that will bring in a new Wolverine after Hugh Jackman retires. However, before that, the US will have to get its hands on the metal. To do that, CIA director Val will form the Thunderbolts team and send them to extract the metal in their own film.6. The Serpent SocietyThe Serpent Society may appear in Captain America 4 (Image via Marvel)The rumor comes from insider Jeff Sneider. While speaking on The Hot Mic podcast, he claimed that before employing the Thunderbolts team in their film, Val would be working with five villains to form the Serpent Society in Captain America 4.This is a villainous team from the comics that is known to fight Captain America. The squad includes villains like Viper, Princess Python, and Diamondback, among other snake-named villains. However, it will be interesting to see which of these villains will form the Serpent Society in Captain America 4.Many fans have theorized that the New World Order might bring Hydra back, but it is going to be the Serpent Society who will instead show up in the film. Moreover, they will be tasked with getting their hands on Adamantium, while team Captain America will try to stop them.Captain America 4 releases on May 3, 2024.