The movie is set one year after Ultron'sattack. SHIELD leaks have raised awareness of the circumstances of severalincidents such as the Battle of New York, the Mandarin bombings, the Dark Elfinvasion, which, in addition to the Hulk rampage in South Africa and Ultron levelingSokovia, have caused superheroes to experience a sizeable public backlash.Stark is retired from being Iron Man and dedicating himself to philantrophy toatone for his mistakes.
Captain America is leading the New Avengers- Black Widow, Falcon, War Machine, Scarlet Witch and Vision - to take down theremnants of HYDRA and find Bucky, aided by Nick Fury.
The movie opens with them busting a drugdeal and recovering some Vibranium-based weaponry. Back to their newheadquarters, the Avengers get to mingle. Black Widow is the co-leader, Falconand Captain America are truebros, and Falcon also has a sort of friendly rivalry with Rhodessince they're both airmen. Cap is coaching Wanda into dealing with her powersand losing Pietro, and Vision is dealing with his expanding consciousness.
Fury drops by to share some info on Bucky.He's been killing HYDRA officials all over the globe, and it's getting hard tokeep track of him or cover up his assassinations. Lots of the HYDRA assets he'soffed are power players with seemingly spotless records, and the publicwouldn't understand.
We then see Spider-Man's first publicappearance catching some criminals, which switches to a Congress hearingdiscussing the matter, with some politicians advocating for the SuperheroRegistration Act. Stark is in attendance alongside T'Challa, who is acting as aspokesman for Wakanda on the matter of the Vibranium stashes that have beenexposed by Ultron's attack. The UN believes Vibranium to be a dangerousresource and wants to oversee its mining and safekeeping, but T'Challa defendsit belongs to his people. The usual political intrigue.
Cap and Stark meet to discuss the Vibraniumweapon usage and discuss the concept of Registration, with Stark supporting itand Cap being against it. They discuss their motives. Meanwhile, in HYDRA'smain lair, Zemo kills people who have failed him. Crossbones is there. Zemosays they in fact didn't fail, but it needed to appear so, because he doesn'ttrust anyone. And it's time to put their plan in motion.
Acting on a tip from one of his contacts,Bucky arrives at a HYDRA outpost in London,where he is ambushed by mercenaries. It's a set-up. The fight spills into thestreet, where Crossbones arranges a bombing to make it appear as if Buckycaused it. The explosions kills several people and causes widespread damage.Bucky escapes, and the Avengers move in to clean up the damage. The publicoutcry is massive, and the SHRA is approved. Stark decides to support it. He haslearned from going through SHIELD leaks that Bucky killed his father and wantsto bring him in.
In his farm, Hawkeye is attacked andcaptured by Crossbones, who kills his wife. He's then taken to HYDRA's lair andtortured for infomation in Fury's secret network, which only Barton is privyto, but doesn't break.
Cap is called to Stark's office, where hemeets CIA asset Peter Gyrich, from London,who has been partnered with Sharon Carter. They announce the Registration hasbeen approved and Cap and his team need to surrender. Cap says "no".Stark tells Steve he's bringing Bucky down, Cap says Bucky is innocent,brainwashed and needs help. Gyrich orders soldiers to seize up Cap, but heescapes.
Cap returns to HQ and tells the others whathappened. He gets into an argument with Black Widow, who believes they need toregister. They exchange harsh words, and when the military come to collectthem, Cap leaves with Sam, Wanda and Vision while Natasha and Rhodes staybehind and join the Registration.
Fury sets up the Avengers in a safe housewhile Stark approaches Spider-Man to join the Registration. Spider-Man confideswith Stark his secret identity, and Stark is surprised to learn he's just aboy. They bond, and Peter mentions Uncle Ben and his mantra that "Withgreat powers, come great responsabilities". Stark then unveils his team onpublic TV, while Cap and his team become fugitives. Their top priority is tofind Bucky before Stark.
Fury gets a lead on Bucky's whereabouts andthe team heads there, but it is an ambush by Stark and his forces, leading to afight. Stark has a new Bleeding Edge armor, but Vision holds his own. ScarletWitch BTFOs some soldiers and Spider-Man, Falcon VS. War Machine, and Cap VS.Widow while she tries to get him to see things from her point of view. ScarletWitch manages to blow them back long enough for her team to escape and reunitewith Fury, who deduces Romanoff used her intel to forge a Bucky sighting to getthem into a vulnerable place.
Cap doesn't want to endanger anyone else,but they all decide to stick to their guns and help him. Stark learns from Rhodes about the Vibranium weapons they busted from HYDRA,and Gyrich reports it to his superiors. They accuse Wakanda of endangeringglobal security by not giving them entrance, and tensions escalate.
Bucky finds out about the Vibranium crisisand goes through his old contacts, eventually locating a HYDRA outpost wherethey storage Vibranium stolen from Wakanda before shipping it off to the otherbases to produce weapons. Stark locates Bucky and tries to bring him in,leading to a fight in which Bucky gets pretty roughed up, but escapes. With noother option, he makes his way to the safe house where Steve is located, whichhe's aware of due to his extensive research on the SHIELD leaks, and tells himeverything.
The New Avengers patch Bucky up and he andSteve finally talk it out. We get some exposition on Zemo and the reaffirmationof the Steve/Bucky broship. Meanwhile, Stark reports to his superiors about theHYDRA stealing Vibranium from Wakanda to produce weapons. T'Challa assures thatthey'll handle it on their own, but the government is undeterred and Gyrichorders the government Avengers to attack Wakanda, which Stark reluctantlyagrees to do. Sharon, who is often at odds with Gyrich over his M.O, contactsFury through a secure line and relays the info to Steve, saying she has faithin him.
Meanwhile, Hawkeye escapes from Zemo's holdas we've established.Stark's Avengers arrive on Wakanda to seize the Vibranium,leading to tensions with the Wakanda military despite their efforts to maintainpeace. Steve's Avengers intervene to stop them from causing an internationalincident and instead shut down the HYDRA outpost collecting Vibranium. Anotherfight ensues, in which Maria Hill is outed as a mole who sabotages the BleedingEdge armor, leveling the game for Steve and Stark to have a big fight. Theother Avengers fight as well, and it spills into the street.
Steve notices that, while everyone isbeating eachother, Spider-Man has peeled off and is rescuing civilians. Herealizes they're fighting for themselves, not for the people, and they need towork together if they want to stop HYDRA. Natasha, who had been having somedisagreements with Stark, vouches for Cap as they realize they're strongertogether than apart.
T'Challa intervenes and volunteers toassist them in stopping HYDRA because he wants peace between his father'scountry and the United Nations. The Avengers, however, do not find the HYDRAoutpost. It was all a dupe so they'd kill each other for Zemo.
Hawkeye manages to contact Fury and reportto the location of Zemo's lair: Switzerland.The Avengers head there and rendzevous with Barton as they mount a massiveattack on Zemo's compound. Zemo orders his men to fight back usingVibranium-based, reverse-engineered weapons from the Chitauri and Ultron, andthe battle is fierce.
Hawkeye fights Crossbones and kills himwith four arrows, one for each of his dead family members. Black Panther kicksass. Wanda eventually manages to achieve enough control over her powers sherearranges the molecules of the HYDRA mooks weapons, culling the Vibranium'sspecial properties and allowing the Avengers to solo them.
Cap and Bucky tag-team Zemo and hisVibranium sword, but Zemo still kicks a lot of ass while rambling about hisideals. He eventually gets defeated and Bucky moves in for the kill, butdecides to spare him, and prove that he is more than the assassin HYDRA forcedhim to become.
Zemo and his men are locked up, and Starkretrieves the location of all of HYDRA's secret bases. The military move in todismantle the entire organization, arrest its figureheads and aprehend theirweapons and technology.
The Avengers are still wanted, but Starkdecides to let them go, and Fury and Jason produce new identities for them tolay low. Vision decides to leave the Earth. Cap decides to surrender, butentrusts his shield to Bucky, so he can always remember who he really is: ahero.
Cap is arrested. Barton finds out hischildren have survived and leaves with them and brings Wanda along to look outfor her as well. Natasha and Rhodes are back with Stark, while Fury disappearsonce again, now with Hill by his side. Peter realizes he isn't made to fight inwars, he's there to look out for the common man, and Stark sends him off,erasing his data from the registry.
Stark BTFOs Gyrich, announces he's takingover because Gyrich made illegal calls throughout his involvement with theSHRA, and Carter is promoted to his place. Stark visits Cap and they patchthings up, Zemo is locked up in the Raft, Natasha visits Cap and they patchthings up, Bucky keeps the torch alive.