Full story
In 1992, in Oakland, King T'Chaka visits his brother, Prince N'Jobu, who is working undercover in the United States. He learns N'Jobu helped arms dealer Ulysses Klaue steal vibranium from Wakanda. In the argument, N'Jobu pulls a gun on Zuri, who had been spying alongside him, and T'Chaka kills him. N'Jobu's young son is left behind, knowing nothing.
In the present, after his father's death in Vienna, T'Challa returns to Wakanda to be crowned. The country pretends to be poor but hides the most advanced technology on the planet thanks to vibranium. At the ceremony, M'Baku, leader of the Jabari tribe, who live apart in the mountains, challenges T'Challa to ritual combat without the powers of the heart-shaped herb. T'Challa wins and talks M'Baku into yielding. At his side are General Okoye, head of the Dora Milaje, his ex Nakia, a spy who wants to help refugees, and his sister Shuri, the genius who builds the weapons and suits.
Klaue resurfaces stealing a vibranium artifact from a London museum with help from an American mercenary. T'Challa, Okoye and Nakia head to Busan, South Korea, where Klaue tries to sell it to CIA agent Everett Ross. After a car chase, T'Challa catches Klaue, but the mercenary breaks him out. Ross takes a bullet protecting Nakia, and T'Challa brings him to Wakanda, where Shuri heals him. Zuri finally reveals the secret of 1992. The mercenary is Erik Stevens, Killmonger, N'Jobu's son, a former U.S. soldier trained to topple governments.
Killmonger kills Klaue and arrives in Wakanda with the body as a gift. He reveals he is N'Jadaka, the king's cousin, and claims his right to the throne. He wins the ritual fight, kills Zuri and throws T'Challa over a waterfall. On the throne, he takes the heart-shaped herb, orders the rest burned and gets ready to ship vibranium weapons to uprisings around the world. Nakia saves one last herb. With Shuri, Queen Ramonda and Ross, she flees to the Jabari mountains, where they find T'Challa in a coma. M'Baku saved him.
Healed by the herb, T'Challa returns and resumes the fight. Shuri, Nakia and Okoye fight beside him. Ross remotely flies a jet to shoot down the planes carrying the weapons. W'Kabi, T'Challa's friend who backed Killmonger, stands down when Okoye faces him, and the Jabari arrive to turn the battle. In the vibranium mine, T'Challa shuts down his cousin's suit and wounds him fatally. Killmonger refuses to be healed and chooses to die free, watching a Wakandan sunset. T'Challa decides to change the country's ways and opens an outreach center in Oakland, in the same building where his uncle died. In the credits, he announces at the U.N. that Wakanda will share what it knows with the world, and Bucky Barnes wakes up in a village under Shuri's care.