HYDRA, thought to have been defeated in World War II, had survived and infiltrated S.H.I.E.L.D., and planned to use Project Insight to create a new world order. Captain America exposed HYDRA's existence to S.H.I.E.L.D. and with the help of Falcon and Maria Hill, terminated Project Insight while Black Widow leaked all of S.H.I.E.L.D.'s files to the public domain.
- "We need to link all three carriers for this to work, because if even one of those ships remains operational a whole lot of people are gonna die."
"We have to assume everyone aboard those carriers is HYDRA. We need to get past them, insert the server blades, and maybe, just maybe, we can salvage what's left–"
"We're not salvaging anything. We're not just taking down the carriers, Nick, we're taking down S.H.I.E.L.D."
- ―Maria Hill, Nick Fury, and Steve Rogers[src]
The attack on Nick Fury made Captain America a fugitive from S.H.I.E.L.D. by order of Alexander Pierce, because Rogers would not give Pierce the USB drive that Fury had entrusted to him. This drive was recovered by Black Widow and given to Fury after the hijacking of the Lemurian Star.
Natasha Romanoff became a fugitive for assisting Rogers and decrypting the USB drive at Camp Lehigh. There she and Rogers learned the secret of S.H.I.E.L.D. from Arnim Zola: HYDRA had been rebuilt inside of the law-enforcement agency, operating clandestinely within its ranks and wreaking havoc across the globe. This insidious resurgence had been in progress since the collapse of the Red Skull's initial incarnation, following his apparent death at the hands of Captain America.
The two needed an uncompromised ally, so they recruited Sam Wilson, a United States Air Force Special Operations Pararescueman that Rogers knew. After laying low at his home, they told Wilson their circumstance and Wilson disclosed his history with the mechanical wings. The three then planned to acquire the mechanical wings so Wilson could help them on their mission.
The Winter Soldier, a legend in the espionage community, was revealed to be Bucky Barnes, Steve Rogers' long-lost best friend. Barnes was incorrectly believed to have been killed in action following a raid on a HYDRA train in late 1944.
Arriving at World Security Council
Pierce invited the World Security Council to Washington, D.C. to witness the launch of Project Insight, a project of S.H.I.E.L.D., corrupted by HYDRA, that would preemptively locate and fire upon dangerous targets by three next-generation Helicarriers.
Launching the Insight Helicarriers
The battle began when Captain America, Falcon, and Maria Hill infiltrated the Triskelion's communications room. Rogers used the intercom to notify all of the agents and employees in the building of HYDRA's plot, urging them to stop the launching of the Helicarriers.
HYDRA agent, Brock Rumlow, ordered the launch be preempted in response, but the technician refused. Agent Sharon Carter pulled her sidearm on Rumlow. He cut her hand with his knife and stole her gun after a tense standoff involving numerous HYDRA and loyal S.H.I.E.L.D. agents. This action caused a shootout between the two factions, during which Rumlow was able to escape. Rogers and Falcon then boarded the Helicarriers as they were beginning takeoff.
Meanwhile, in the World Security Council room, Alexander Pierce's identity had been revealed to the other council members due to Rogers' speech. The council members were further shocked when STRIKE agents loyal to HYDRA filled the room and held them all at gunpoint. Pierce asked Councilman Singh if he would be against Project Insight's true goals, if the same methods were used to save his daughter from execution. Singh curtly replied he would, much to Pierce's amusement. When Pierce prepared to shoot him, Councilwoman Hawley suddenly attacked Pierce and his men, single-handedly taking them all down. She then held a shocked Pierce at gunpoint, and revealed herself to be none other than Black Widow in disguise.
Meanwhile, Rogers and Wilson managed to replace the targeting blades on two of the three Helicarriers. While working on the third carrier, Rogers and Wilson were attacked by the Winter Soldier. Wilson was thrown off the ship and managed to parachute to safety on top of the Triskelion, but his suit was damaged beyond repair. Rogers remained on the ship and headed for the control room.
Releasing S.H.I.E.L.D. Files
In the Council chamber, Natasha Romanoff disabled the computer security and dumped classified information onto the Internet, exposing HYDRA's infiltration to the world. Alexander Pierce pointed out that it would also expose S.H.I.E.L.D.'s and Romanoff's dirty business in the process, but Romanoff was undeterred. Pierce realized that such a declassification of information required two Alpha-level members of S.H.I.E.L.D. for authorization. Just then, Nick Fury arrived by helicopter and confronted Pierce. Pierce attempted to convince Fury that their ambitions were the same, but Fury refused to listen and forced Pierce to deactivate the security along with him.
Steve Rogers confronted Bucky Barnes in the control room. After attempting to persuade Barnes to relent, Rogers engaged him in brutal hand-to-hand combat. The two fought until finally Rogers broke Barnes' shoulder and partially suffocated him. While Rogers attempted to replace the chips in the system, Barnes shot him from below.
Pierce then used his phone to activate the white phosphorus-laced biometric identification tags the Council members were wearing, burning through their flesh, damaging their internal organs, and killing them. Romanoff, having disguised herself as Hawley, was forced to drop her gun due to the tag on her chest.
Destruction of the Helicarriers and the Triskelion
When the Helicarriers reached three thousand feet above mean sea level, Steve Rogers and Bucky Barnes synced to their targeting satellites in orbit. They acquired thousands of targets, employing Arnim Zola's algorithm to find and track them. Just as the ships' long-range precision guns were ready to fire, a wounded Rogers replaced the last targeting blade, disabling the control systems in the carriers. This allowed Agent Hill to take remote control of the Helicarriers, promptly redirecting the ships to fire on each other. The Helicarriers began to destroy each other and kill the HYDRA agents on board, with Rogers and Barnes still trapped on one of them.
Alexander Pierce intended to make his escape, using Natasha Romanoff as a hostage. However, Romanoff activated a Taser Disk in her hand, which sent a current through her body and disabled the tag on her chest. Romanoff collapsed to the floor, and as Pierce tried to reactivate the tag, Fury picked up a gun and shot Pierce dead.
Brock Rumlow headed for the Council room and Maria Hill ordered Falcon to head him off. The two engaged in hand-to-hand combat following an ambush by Falcon, but their fight was interrupted by one of the falling Helicarriers crashing into the building. Rumlow was buried under the cascade of rubble, but Falcon threw himself through a window and landed in a helicopter piloted by Fury.
In the falling Helicarrier, Rogers removed Barnes from fallen rubble, and attempted to convince Barnes of his identity. A confused and infuriated Barnes assaulted Rogers, but suddenly remembered that they were friends when Rogers repeated one of the catchphrases that defined their relationship. Rogers fell from the Helicarrier as debris caused the floor to collapse under him, although Barnes did not. Rogers landed in the Potomac River. He was saved from drowning by Barnes, who helped him ashore and vanished from sight. Rogers was later hospitalized, along with Rumlow.
Due to the information that Black Widow had shared across the Internet, S.H.I.E.L.D. was labeled a terrorist organization and was disavowed by the international community. No reasons were given for why Captain America took down the Helicarriers, leading some people to question whether the Avenger had really saved them from tyranny or just wanted them to think that he had.
Congressional hearings were held to question various S.H.I.E.L.D. agents, including Romanoff and Hill. Both managed to avoid imprisonment, with Romanoff declaring that they needed her, and could not afford to lock her up. The hearing committee allowed her to leave. Maria Hill managed to obtain a job at Stark Industries, although she was still pursued by the FBI. Nick Fury, meanwhile, continued to live in secret, with the world still believing him to be dead.
With HYDRA's infiltration of S.H.I.E.L.D. now known, HYDRA scientist, Doctor List, worried that HYDRA's work in Sokovia would be discovered. His superior, Baron Wolfgang von Strucker, assured him that HYDRA would keep Captain America and the other Avengers distracted so that they would be able to continue their work.
HYDRA operatives throughout S.H.I.E.L.D. were tasked with purging all S.H.I.E.L.D. facilities of non-HYDRA personal while S.H.I.E.L.D. agents fought back. Eventually two factions of S.H.I.E.L.D. rose up. One was lead by Phil Coulson and the other was lead by Robert Gonzales. This division led to a S.H.I.E.L.D. Civil War.
The civilian community partially blamed President Matthew Ellis for the debacle. Eventually, President Ellis commissioned the creation of the Advanced Threat Containment Unit, since S.H.I.E.L.D. had caused damage to Washington, D.C. and had threatened the United States as a whole.
Repairs began in Washington, D.C. following the incident and continued until as late as May 3, 2016. On that date, Washington, D.C. was among the cities noted by WHiH News anchor, Christine Everhart, as being still "on the mend" as a result of the incidents involving the Avengers. The issue of the Avengers' management and responsibility was being discussed.
The Battle at the Triskelion was cited by Thaddeus Ross as one of a series of high-profile incidents involving the Avengers that ultimately culminated with the passing of the Sokovia Accords which led to the Avengers Civil War.
|Appearances for Battle at the Triskelion|
In chronological order:
- Captain America: Civil War
- Captain America: The Winter Soldier
- Agents of S.H.I.E.L.D.: 1.18: Providence
- Spider-Man: Homecoming Deleted Scene
- Agents of S.H.I.E.L.D.: 1.20: Nothing Personal
- Captain America: The Winter Soldier Mid-credits Scene
- Captain America: The Winter Soldier Post-credits Scene
- Agents of S.H.I.E.L.D.: 1.17: Turn, Turn, Turn
- Agents of S.H.I.E.L.D.: 1.19: The Only Light in the Darkness
- Agents of S.H.I.E.L.D.: 3.01: Laws of Nature
- WHIH Newsfront Exclusive: President Ellis Discusses the Avengers
- Spider-Man: Homecoming