In 2010, the Roxxon Oil Corporation oil tanker Norco spilled a million gallons of crude oil off the coast of Pensacola. Matthew Ellis used his political influence to avoid that the Roxxon executives were judged and imprisoned for the event.
Acquisition of the Norco
Aldrich Killian acquired the Norco to use it as an excuse to kill President Matthew Ellis and make it seem as a Mandarin terrorist action for political reasons due to Ellis' role in the aftermath of the oil slick.
Arrival of President Ellis
Aldrich Killian arrived at the Norco and checked Pepper Potts, who had been injected with Extremis and was held prisoner inside the ship, and revealed that she was taken captive not just to motivate Tony Stark into stabilizing Extremis, but actually as Killian's personal trophy.
Killian greeted President Matthew Ellis as he was taken to the ship inside the Iron Patriot Armor, who recognized the ship as the Roxxon Norco. Killian told his motives to retain Ellis in the ship, as he did not want to negotiate for Ellis' life; he intended to kill him masquerading as a Mandarin terrorist attack in order to let Vice President Rodriguez, secretly in league with Killian, to become the new president.
Arrival of the Iron Legion
Tony Stark and James Rhodes were able to board the ship, but where outnumbered as the tanker was guarded by a large squad of Extremis Soldiers. Rhodes located President Matthew Ellis, tied inside Rhodes' Iron Patriot Armor waiting for his public execution.
Stark and Rhodes were spotted by the soldiers, and forced to take cover, while starting to be surrounded by the soldiers. Stark grew confident as a humming noise was heard approaching, and Rhodes asked if it was what he believed it was. A whole legion of Iron Man Armors surrounded the ship, as the much needed backup for Rhodes and Stark.
Stark ordered J.A.R.V.I.S. to target the soldiers due to their unique heat signatures, and ordered to neutralize them with the maximum prejudice. The armors started battling the soldiers, gaining the upper hand though some of the armors were destroyed during the fight. Stark also defined some of the battle strategy for the armors, such as ordering the Mark XXXVIII to stabilize structure of the oil tanker.
Stark donned one of his armors to battle himself, but did not let Rhodes wear one as they were explicitly coded for Stark. An armor controlled by J.A.R.V.I.S. carried Rhodes, but they were attacked by a soldier and forced to jump to one of the footbridges. A pair of Extremis soldiers attacked him, but Stark's armors easily defeated them before they could harm Rhodes.
Stark went on to rescue Pepper Potts, still tied inside the tanker, but she was hit by one of the explosions and was trapped under a large amount of debris, but Killian himself attacked Stark and disabled the Arc Reactor of the armor using his advanced Extremis abilities, and taunted Stark due to his inability to defeat him in front of Potts, but Stark waited until the last moment and cut Killian's arm. The arm started to melt the ship due to its high temperature, and make Potts fall through the open hull.
Rhodes went to save President Ellis and defeated a pair of Extremis Soldiers, tricking them into falling from the container they ambushed him. Rhodes liberated the president, and recovered his armor. As Iron Patriot, Rhodes rescued Ellis and took him outside the ship. Meanwhile, Stark rushed to save Potts. He tried to convince her to let go as Stark will catch her and prevent her falling, but the debris moved and Potts fell to her seeming death, leaving Stark devastated.
Killian reappeared unharmed and having recovered his arm, and taunted Stark again for letting Potts die. Stark angrily confronted Killian, using different armors that were destroyed by Killian, and avoiding a fatal blow in a scenario parallelized by Killian to the roof in Bern where they never met.
Stark waited as the Mark XLII armor approached, but it crashed against an obstacle and disassembled into pieces. Killian, prepared to kill Stark, taunted him for what he thought it would be the last time, but Stark answered him in order to buy some time, telling Killian that it was right that Stark didn't deserve Potts, but there was no need to improve her, as she was already perfect. Stark ordered the Mark XLII to be worn by Killian, and asked J.A.R.V.I.S. to trigger the self-destruction of the armor to kill Killian.
Killian survived the explosion, and reappeared before Stark claiming that he was the Mandarin, but was confronted by Potts, who also survived her fall. One of the armors approached, intending to attack Potts recognizing her Extremis heat signature, but she angrily destroyed it with a single punch, tearing apart the repulsor gauntlet and using it to detonate a missile that he launched to Killian, finally killing him.
Stark and Potts, relieved by the end of the battle, discussed what they would do after that, as Potts finally understood Stark's obsession with the armors. Potts was worried to hurt Stark due to Extremis, and promised her to help her without distractions, as he ordered J.A.R.V.I.S. to destroy all his remaining armors.