*CUT TO THE CHASE*
NOTE: This spoiler was submitted by Jeremy
The film opens with a man telling his son the history of their people. Long ago, a meteor containing vibranium crash-landed in Africa. Five tribes began to fight over the vibranium until one of the shamen spoke to the panther god Bast and ingested an herb that gave him the power to become the first Black Panther. The man united the tribes to create the nation of Wakanda, leading him to become king. However, the Jabari tribe chose to take refuge in the mountains, distancing themselves from the other tribes. The Wakandans used vibranium to develop highly advanced technology and chose to isolate themselves from the rest of the world by producing a force field that hides the nation from sight.
1992, Oakland, CA - Two men, N'Jobu (Sterling K. Brown) and James (Denzel Whitaker), are planning to move weapons across the city. A knock is heard at the door. James opens it to find two Dora Milaje warriors. N'Jobu recognizes them and reveals himself as a Wakandan. Entering the room with the warriors is King T'Chaka (Atandwa Kani), N'Jobu's brother. T'Chaka asks N'Jobu to come home after being sent to California as a spy to catch Ulysses Klaue (Andy Serkis), but N'Jobu has other plans. T'Chaka then reveals that James is actually Zuri, another Wakandan spy. They discover that N'Jobu has stolen vibranium for himself, and they will bring him back home to put him on trial for his crimes. Outside on the courtyard, a group of children look up to the sky to see T'Chaka's ship fly overhead.
In the present day, T'Challa (Chadwick Boseman) is set to become king after T'Chaka's (now played by John Kani) death. He is flying over Nigeria with Okoye (Danai Gurira), a Dora Milaje general. The plan is to extract his ex-girlfriend Nakia (Lupita Nyong'o) as she is undercover with mercenaries smuggling women and young men as soldiers. As Black Panther, T'Challa jumps out of the jet and uses Wakandan tech to disable the mercenaries' vans. As the goons step out to confront T'Challa, he fights them all before finding Nakia. She joins T'Challa and Okoye as they return home.
The three return to Wakanda and reunite with T'Challa's mother Ramonda (Angela Bassett) and his younger sister Shuri (Letitia Wright) in preparation for T'Challa's ceremony to become the new king. All of the tribes gather by a waterfall to witness. Zuri (now played by Forest Whitaker) gives T'Challa a drink that removes the power of the Black Panther. With that, nobody from the other tribes chooses to challenge T'Challa, until the Jabari tribe show up, and their leader, M'Baku (Winston Duke), steps up to try and take the throne from T'Challa. The two fight, with M'Baku almost succeeding until T'Challa gains the upper hand and puts M'Baku in a hold over the falls until he taps out and surrenders, allowing T'Challa to rightfully claim the throne.
After the ceremony, T'Challa is given another drink to restore his powers before being buried in sand so that he may be taken into the ancestral plane. There, T'Challa sees his father. They embrace as T'Challa breaks down upon seeing him. T'Challa expresses his concerns over becoming king and doing the right thing. T'Chaka tells his son that while he is a good man, it is hard for a good man to be king.
In London, Erik "Killmonger" Stevens (Michael B. Jordan) is at a museum admiring artifacts from African cultures. He asks the guide about a hammer-like weapon, which she identifies as one thing, but Killmonger corrects her and says it is made of vibranium from Wakanda. The guide then passes out from a something Killmonger slipped into her coffee in order to create a diversion. Medics arrive, but they are really Klaue and his goons. They kill the guards, and Killmonger steals the weapon before getting away with his crew.
T'Challa walks through downtown Wakanda with Nakia. He asks her to stay home to help him run things around there, but she shows hesitance in continuing to work in Wakanda. Later, T'Challa is with his best friend W'Kabi (Daniel Kaluuya) as they check on a wild rhino in a pen. They are then called by Okoye (who is also W'Kabi's lover) to the palace. Klaue is set to sell the vibranium piece to an American buyer in South Korea that night. W'Kabi wants to join T'Challa in finding Klaue, as he murdered W'Kabi's parents, but T'Challa asks that he stay and keep things secure while he goes.
Before the mission, T'Challa meets with Shuri, who has developed a number of impressive technology, including sound-absorbent shoes (which she calls..."sneakers"), as well as modifications to the Black Panther suit. It is disguised as a necklace and it absorbs each hit it takes and turns it into kinetic energy.
T'Challa, Nakia, and Okoye go undercover in Busan to a casino where they try to find Klaue and his buyer. T'Challa runs into Everett Ross (Martin Freeman), who is also undercover. Klaue and his goons show up, and he quickly realizes he is being set up. Okoye is compromised by one of Klaue's men, forcing her to fight them. Klaue and his men escape and ride through the streets, leading Nakia and Okoye to pursue them. T'Challa follows in his suit while Shuri rides a car through a projection back home that operates an actual car that T'Challa rides on. The villains shoot at him, but the hits from the bullets give him the kinetic energy that he redirects to the villains. Klaue blasts at Nakia and Okoye, destroying their car but not killing them. T'Challa reaches Klaue's car and rips out a tire, causing him to crash. T'Challa goes to finish Klaue, but Nakia reminds him that people are watching. They take Klaue into custody.
Ross interrogates Klaue while T'Challa and Okoye listen in through a device T'Challa planted on Ross. Klaue reveals to Ross what he previously didn't know about Wakanda and all that it contains. Outside, Killmonger and his crew set up explosives behind a wall. Nakia sees this on security cameras and runs to warn everyone, but the villains blow open the wall. They start shooting, and Ross pushes Nakia out of the way, taking a bullet in the back. Killmonger takes Klaue away, and T'Challa notices a ring around Killmonger's neck similar to one that belonged to his grandfather.. Ross is given something to keep him stabilized until they return home.
The villains head to a plane that Killmonger wants to take to Wakanda. Klaue takes Killmonger's girlfriend as a hostage since he has other plans, but Killmonger kills the woman himself before shooting Klaue. He tells Killmonger they won't let him into Wakanda until he reveals a tattoo on his lip that most Wakandans have. He then shoots Klaue dead.
Back in Wakanda, W'Kabi expresses disappointment with T'Challa for failing to bring in Klaue. At the same time, Ross is being tended to by Shuri, who uses vibranium to heal his wounds. T'Challa then goes to find Zuri and ask him why Killmonger had his grandfather's ring. Zuri is then forced to admit what he knew about N'Jobu. In a flashback to 1992, we see that N'Jobu had stolen the vibranium to spread it to other people of African descent so that they may fight back against their oppressors. N'Jobu turned his gun on Zuri, and T'Chaka stepped in and killed N'Jobu with his claws. It filled T'Chaka with great regret, and they left his son, Erik, behind. The boy was on the courtyard when this happened, and he later found his father's body. Erik would go on to become a black ops soldier who earned the nickname "Killmonger" due to his high body count, which is evident by the marks on his body for everyone he's ever killed.
Killmonger enters Wakanda with Klaue's corpse. He presents it to W'Kabi, who escorts Killmonger to the palace. Killmonger reveals his true name, N'Jadaka, and that he is N'Jobu's son. W'Kabi confirms it to everyone when he shows them Killmonger's ring. He announces his intention to claim the throne, and he challenges T'Challa for the spot.
Everyone gathers for the challenge by the falls once again. Killmonger fights brutally and almost easily overpowers T'Challa. Zuri steps in to try and save T'Challa, knowing it is with him that Killmonger should hold a grudge. Killmonger fatally impales Zuri and takes T'Challa down before throwing him over the falls, to the horror of Ramonda, Shuri, and Nakia. Thus, Killmonger is made king.
Killmonger goes into the ancestral plane and is back in his old apartment where he sees the moment that he found his father's body. He comes across N'Jobu's old journals and even speaks to the man himself briefly. After waking up, Killmonger orders everyone to burn a garden of heart-shaped herbs for future kings, but Nakia manages to sneak one away with her.
Nakia goes with Ramonda, Shuri, and Ross to the mountains to find the Jabari tribe. They speak to M'Baku and ask for his help. He reveals to the group that they fished T'Challa out of the river, and that he is now in a coma. Ramonda grounds the herb into a drink to give T'Challa before they bury him in the snow that he rests upon. He goes into the ancestral plane and sees T'Chaka again, this time condemning his actions in leaving Killmonger behind. T'Chaka admits that this was the truth he hid from his son, and he expresses regret. T'Challa then wakes up. He requests M'Baku's help in fighting Killmonger, but he refuses.
Killmonger now has help from W'Kabi and other Wakandan soldiers as he plans to send their weapons across the world to other operatives and mercenaries as his father had planned. As one of their jets flies overhead, it is shot down by T'Challa, making his return as Black Panther. W'Kabi and his army charge against T'Challa, but he blasts them away with his kinetic energy. Okoye then leads the Dora Milaje into battle. Shuri gives Ross access to a jet to take down the others before they leave Wakanda. Ross is able to shoot them all down. Nakia joins Shuri and Okoye as they fight Killmonger, now in his own suit. W'Kabi unleashes armored rhinos into the battle. Suddenly, the Jabari arrive to help the Dora Milaje. One of the rhinos nearly runs down M'Baku until Okoye steps in. She forces W'Kabi and his soldiers to surrender.
Before Killmonger can hurt Shuri, T'Challa tackles him and they fall down into the vibranium mines. They continue their fight until T'Challa utilizes the tech down there to mess with Killmonger's suit, leaving him exposed so that T'Challa may impale him with his own short spear. Now vulnerable and dying, Killmonger expresses regret over not seeing how beautiful Wakanda really is. T'Challa carries Killmonger out of the mine to see the sunset, which N'Jobu had described to him as a sight to behold. T'Challa offers Killmonger a chance to be healed, but he declines, knowing he would only be imprisoned afterwards. Killmonger requests to be buried at sea with his ancestors, as they knew death was better than bondage. He pulls the spear out of his chest and dies peacefully.
Things become calm once again in Wakanda as T'Challa reclaims his throne. He once again asks Nakia to stay in Wakanda, as he has plans for her to help him. The two of them kiss.
T'Challa brings Shuri to Oakland outside Killmonger's old apartment. T'Challa reveals he bought the building, as well as two buildings next to it so that he may establish a Wakandan outreach program that Nakia and Shuri will spearhead. He then brings down their jet so that the kids in the courtyard may see and be in awe of. One of the boys then approaches T'Challa and asks him who he is.
Mid-Credits Scene: T'Challa is joined by Nakia, Shuri, and Okoye at the United Nations. He announces his plan to bring Wakanda out of hiding in the hope that they may work together with the rest of the world.
Post-Credits Scene: Three Wakandan children are looking upon someone in a hut. Shuri orders them to not bother the person. He steps out of the hut, and we see it is Bucky Barnes (Sebastian Stan).