Clash of the Avengers

The Clash of the Avengers was the first open confrontation between the two factions that once made up the Avengers. The battle started when Iron Man and War Machine intercepted Captain America and Winter Soldier at Leipzig/Halle Airport to enforce the Sokovia Accords, escalating into a battle after a heated argument with neither side backing down.

Background
Bucky Barnes had been framed for a bombing attack on the Vienna International Centre the day the Sokovia Accords were being signed. Barnes' friend, Captain America, brought it on himself to bring Barnes in, knowing that ordinary humans would not survive an encounter with a super soldier, especially one that had once nearly beat him to death. However, he discovered that Barnes could not have been in Vienna at the time of the bombing, and he was therefore innocent. A chase through Bucharest only resulted in Barnes, Captain America, Falcon, and Black Panther being arrested. All four were escorted to a Joint Counter Terrorist Centre Building; the two Avengers and Black Panther were placed in an office and had their equipment confiscated, while Barnes was heavily restrained in a mobile cell, to be interrogated.

Prior to Barnes' interrogation, Theo Broussard, the psychiatrist who was supposed to be carrying out the interrogation, was murdered by Helmut Zemo, the true perpetrator of the Vienna bombing. Zemo impersonated Broussard, and carried out the interrogation as normal until he was able to speak a trigger phrase intended to activate Barnes' Winter Soldier programming and send Barnes on a rampage; Captain America realized that "Broussard" was an impostor, but was too late to prevent the attack. After killing several Joint Counter Terrorist Centre employees and nearly killing Black Widow, Barnes attempted to escape in a helicopter, but Captain America prevented him from leaving, causing Barnes to crash it. Captain America saved Barnes from drowning after falling into the river, and Barnes' Winter Soldier programming had worn off by the time he awoke.

The Joint Counter Terrorist Centre gave Iron Man 36 hours to capture Barnes and bring in his renegade comrades. Although War Machine, Vision, Black Widow, and Black Panther agreed to help Stark, he still felt undermanned and recruited high school student Peter Parker, who Stark managed to discover was a superhero named Spider-Man, under the pretense of giving him a scholarship under the Stark September Foundation program.

Meanwhile, Captain America and Falcon learned from Barnes that there were five other candidates for the Winter Soldier Program and that a man called Helmut Zemo was headed to the facility where they were being kept in cryogenic stasis. Rogers then asked Hawkeye to retrieve Scarlet Witch from the New Avengers Facility and then recruit Ant-Man, whom Falcon had run into in the past. Captain America's team then made their way to Flughafen Leipzig-Halle Airport, where a Quinjet was waiting to take them to Siberia.

Battle
Iron Man evacuates the airport, alerting Captain America and his team to the heroes' presence. Captain America jogs out onto the runway towards a helicopter, which is then quickly disabled by Iron Man as he, War Machine, Black Panther and Black Widow approach Captain America. Captain America attempts to convince them that Barnes is innocent, however Iron Man grows inpatient and orders Spider-Man to web Captain America's hands and steal his shield. Falcon soon locates the Quinjet and notifies Captain America, who then gives the signal to Hawkeye. Hawkeye fires an arrow at the webbing, freeing Captain America as Ant-Man reveals himself to be hiding on Captain America's shield and manages to take Spider-Man by surprise, hitting him and retaking the shield. Stark turns around to the source of the arrow, locating Hawkeye and Scarlet Witch via scan as War Machine announces Falcon and Barnes position and the battle begins.

Spider-Man, still inexperienced, asks Iron Man what he should do, who repeats that he should keep his distance and shoot web to harmlessly subdue them. Black Panther immediately heads for Barnes' location but is quickly stopped by Captain America, refusing to let him kill his friend. Ant-Man casually and naively tells Black Widow he'd rather not hurt her, Natasha responds by kicking him and spinning him around. Ant-Man quickly reacts by shrinking and flipping her over, however Black Widow zaps and launches him away with her bite.

Spider-Man smashes through the airport's terminal window and kicks Falcon down and effortlessly intercepts a punch from The Winter Soldier's prosthetic arm, revealing his superhuman strength. Spider-Man becomes distracted at the arm until he is tackled by an airborne Falcon, who carries him up into the air. Meanwhile, the fight between Captain America and Black Panther continues, Rogers struggling to hold back both Black Panther as well as War Machine, who takes hold of his War Hammer to joins in on the fight. Black Panther causes a notible claw mark on Captain America's shield using his vibranium claws. As this occurs, Iron Man catches up to Hawkeye and Scarlet Witch, firing missiles around them to force them to stop running. After a brief conversation, Hawkeye distracts Iron Man by purposefully missing arrow shots who allows Scarlet Witch to drop cars from above on top of Iron Man, temporarily immobilizing him.

Back in the terminal, Spider-Man chases Falcon through the room before using his spider-sense to quickly dodge a heavy object thrown from behind him by The Winter Soldier, throwing it back in his direction. Falcon tackles Spider-Man a second time, but maneuvers above him and disables his thrusters with web, causing him to fall to the ground and smash through a stand. Spider-Man quickly webs Falcon's arms to a glass barrier before he can escape and goes on to ask if Falcon's wings are made of carbon fibre. Falcon reminds him that you usually don't have conversations while fighting and Spider-Man responds by swinging towards him in an attempt to kick in in the chest. Barnes quickly runs in front of Falcon to absorb the hit, but both still fall through the glass barrier and onto the floor below before being webbed again by Spider-Man. Before Spider-Man can fully immobilize the two of them with more web, Falcon quietly orders Red Wing to grab his arm and throw him out of the window. Barnes murmurs that he should have done that sooner, to which Falcon replies that he hates him.

Outside the terminal, Captain America kicks War Machine, destroying his War Hammer. Ant-Man joins Captain America and gives him a shrunken down truck filled with fuel, telling him to throw it at one of his blue pym particles disks. Ant-Man throws the disk in the air and Captain America does as he was instructed, the truck grows to its regular size, blowing up and slamming into War Machine shortly afterwards. The two run off and regroup with Hawkeye, Scarlet Witch, Falcon and Barnes as they sprint to the Quinjet. Before they can reach it, Vision arrives at the airport and stops them by firing a warning beam across the floor. Vision uses this time to give Captain America one last chance to surrender, while also giving Iron Man's faction enough time to regroup as well. Captain America refuses to surrender, and begins to charge alongside his faction. Iron Man, also refusing to back down, does the same. The two sides slowly build up speed before they all clash together in combat, eventually splintering off into individual fights.

Among all the other chaos, Black Widow and Hawkeye exchange hits as Black Widow jokingly asks if they're still friends to which Hawkeye responds that it depends on how hard she hits him. Black Widow flips the distracted archer and almost deals a finishing blow to the head before Scarlet Witch intercepts it and throws her a distance into some airport equipment, hurting her and keeping her out of the majority of the battle from that point. Scarlet Witch scolds Hawkeye for pulling his punches before leaving to help The Winter Soldier. Black Panther had immediately began fighting Bucky and refused to listen to anything he said in his own defense. Before Black Panther gets the chance to claw Barnes' neck, Scarlet Witch stops him and throws him away.

Captain America throws his shield and cuts through Spider-Man's webbing as he is swinging around, dropping him to the floor. Spider-Man is once again interested by Captain America's faction's equipment and complains that his shield doesn't obey the laws of physics. Captain America tells Spider-Man that he doesn't understand what's going on, Spider-Man remarks that Stark said he'd say that and begins to follow advice given by Stark on how to beat Captain America. However, despite the advice from Iron Man and Spider-Man's superior abilities, Captain America still comes out on top due to his experience, dropping a plane bridge on top of Spider-Man to temporarily immobolize him.

Meanwhile, Falcon requests help from Hawkeye to get Iron Man off his back. Ant-Man climbs onto Hawkeye's arrow and is launched alongside it, the arrow splinters into several pieces to distract Iron Man as Ant-Man leaps from the arrow, runs up an unsuspecting Iron Man's arm and slides into a crack in his armor. Iron Man, now fighting Hawkeye, begins to have several of his suit's weapons systems go offline. Ant-Man makes his presence inside the suit known as he jokes that Stark will need to bring his suit into the shop, which backfires as F.R.I.D.A.Y. begins deploy the suit's fire supression system, launching him out of the suit before he can cause further damage.

Captain America and Barnes regroup, Barnes reminding Rogers that Zemo had likely entered Siberia at that point and that they needed to move quickly. Captain America offers to distract Vision as The Winter Soldier takes the Quinjet and goes alone, however Falcon, currently being chased by War Machine, tells Captain America that this wasn't the real fight and that he needed to be there for the real one. Hawkeye chimes in, telling Rogers that if they want to win, some of them will have to lose. Falcon explains that they'll need a big diversion if they want to be able to let both Captain America and Barnes escape in the Quinjet, to which Ant-Man responds that he has something 'big'. He tells Captain America to run at his signal, as he jumps onto War Machine's leg and becomes Giant-Man, increasing his size to several stories high and capturing the attention of everyone. He grabs War Machine and throws him across the airport, Spider-Man barely catching him with a string of web before he crashes into a plane. As Giant-Man, Lang begins to kick and throw large objects towards Iron Man's faction, not limited to a plane wing thrown at Iron Man during his fight with Falcon and a bus kicked towards Black Panther (who is narrowly protected by Vision, who blocks the bus just in time) as he attempts to chase The Winter Soldier. Iron Man asks if anyone on his team had any abilities they wanted to disclose before Falcon temporarily closes his wings midflight and launches Red Wing into Iron Man's head, destroying it in the process.

Black Panther is blocked by Giant-Man once again in his attempt to reach Barnes, who kicks him over and is in the process of kneeling down to grab him as he peppered with non-lethal rounds from War Machine, who is carrying Spider-Man. Spider-Man leaps from War Machine onto Giant-Man, swinging around his arm before kicking him in the face. Below, Hawkeye introduces himself to Black Panther after firing multiple arrows at him, to which Black Panther responds that he doesn't care. The two engage in hand to hand combat as War Machine continues to attack Giant-Man, eventually firing his full arsenal at him as he attempts to crush War Machine with a bus.

Vision, after attacking Lang, becomes aware of Captain America and Bucky's escape, and decides to destroy the tower next to the Quinjet's hanger to block the entrance. Scarlet Witch quickly uses her powers to slow down the fall of the debris, until War Machine uses his Stark Sonic Cannon to release a high frequency that incapacitates her. Captain America and Barnes are forced to slide under the debris as it falls, who are greeted by Black Widow as they finally reach the Quinjet. Black Widow comes to terms with the fact that Captain America isn't going to change his mind, and decides to help him by betraying her side by once again using her bite, this time on Black Panther, who had since ended his fight with Hawkeye and given chase.

As the rest of Iron Man's faction are still in the process of fighting Giant-Man, Spider-Man comes up with the idea to lock his legs together similar to the way AT-ATs were beaten in Star Wars: The Empire Strikes Back. Lang, slowed down in Giant-Man form, is unable to respond to Spider-Man flying around his legs tying him up with web as Iron Man and War Machine team up and punch Giant-Man in the head, knocking him down and taking him out of the fight for good (not without accidentally knocking Peter as he fell, however). Stark lands to see if Spider-Man is okay and orders him to go home in case he gets hurt again, thanking him for the job he did.

Piloting the Quinjet, Captain America finishes shooting down the debris in the way of the hanger entrance before leaving, despite Black Panther's best efforts to stop him. Vision flies over to a recovering Scarlet Witch and they apologise to eachother for fighting. War Machine and Iron Man begin following the Quinjet, with Falcon not far behind. Falcon begins peppering War Machine with missiles and Rhodey responds by requesting Vision to disable Falcon's thrusters so he would be forced to safely glide down to the ground. Vision, distracted, fires an abnormally powerful beam at Falcon who quickly dodges it. The beam continues through the air and cuts through War Machine's suit, destroying its arc-reactor and completely disabling the suit. Rhodes, trapped inside the suit and unable to control it, begins to plummet to the earth. Both Falcon and Iron Man stop chasing the Quinjet and fly down in an effort to save Rhodey, but neither are fast enough and he slams into the ground. Tony lands and tears off the helmet's mask, revealing Rhodey to be unconcious. F.R.I.D.A.Y. reads his vitals and informs Stark that he is still alive. Falcon lands and tells Tony that he is sorry. Stark, distraught, blasts Falcon in the chest, signalling the end of the conflict.

Aftermath
The four anti-registration Avengers (Hawkeye, Ant-Man, Falcon and Scarlet Witch) who stayed at the airport were captured and imprisoned in the Raft. Spider-Man was dismissed by Tony Stark and returned to his home in Queens, New York. James Rhodes survived his plummet, but suffered severe spinal injuries that ended his career as both an Avenger and a soldier. Tony Stark meanwhile, went to the Raft to visit Thaddeus Ross. However, shortly after the battle, Theo Broussard, the psychiatrist who was supposed to interrogate Winter Soldier, was found dead in a hotel room accommodated by Helmut Zemo. F.R.I.D.A.Y. relayed the image of Broussard's corpse to Stark while he was en route to the Raft, and also informed him that prosthetics designed to resemble a James Buchanan Barnes, better known as Bucky or the Winter Soldier, had been discovered there. Stark realized that the Winter Soldier had been framed, that it was Zemo who had bombed the United Nations, and that the Avengers had been manipulated into fighting over a falsehood.

Stark attempted to tell Ross this, but Ross was having none of it. Seeing that he would get no help from the proper authorities, Stark decided to take matters into his own hands. He interrogated Sam Wilson on the destination of Steve Rogers and Bucky Barnes, but deliberately caused a temporary audio failure, making it clear that he was no longer an enemy. Wilson told Stark that Rogers and Barnes were headed to Siberia. Knowing that making amends would make him an outlaw, Stark lied to Ross about what Wilson had told him, put on the Mark XLVI armor once out of visual range of the Raft, and flew to Siberia to reconcile, unaware that Black Panther was following him, intending to enact revenge on his father's true killer.