Old Sun

Old Sun refers to the 2014 incident on the Bering Sea, in which Liquid Ocelot attempted to destroy the Patriots' core AI, resulting in a naval battle between Outer Haven and the USS Missouri.

"Everything Ends"
With Outer Heaven leader Liquid Ocelot in possession of Metal Gear REX's rail gun, he had the means to destroy the Patriots' core AI, JD with a nuclear strike. On board the Arsenal Gear-class warship, Outer Haven, Liquid headed out into the Bering Sea, 494 nautical miles from the Bering Strait, in order to strike the U.S. military satellite housing JD. With the satellite orbiting at 10 kilometers per second, and the nuke's damage radius of 300 meters, JD was to be attacked as it reached its perigee in order to conduct an accurate launch.

Briefing U.S. military personnel on board the USS Missouri, navy captain Mei Ling intended to attack the submersible Haven when it surfaced to make its nuclear strike. Though trailing behind the technologically superior warship, the Missouri would be able to catch up to Haven while it made its launch preparations. However, the crew would have to rely on their eyes to locate it, as the Missouri had been stripped of most of her equipment, and also lacked any electronic warfare capabilities. Since a direct attack would be useless, thanks to Liquid's control of the SOP System, a strike team would infiltrate Haven during the assault and upload a worm cluster into the ship's AI, GW. Solid Snake volunteered for the mission, making no secret of his disregard for his own life, along with Meryl Silverburgh and Johnny Sasaki.

Having received intelligence from Naomi Hunter, the strike team planned to catapult aboard the vessel after it opened its top cover to fire the bridge-mounted rail gun. They would then penetrate GW's physical server room and upload the worm cluster, which had been created by Naomi and Sunny. The worm would both prevent the nuclear launch and wipe GW's programming. Since it would need to stay integrated within the Patriots' network, in order to assume JD's functions after its destruction, GW could not be deactivated to prevent the worm's upload. However, the server room would be heavily defended by Liquid's troops, along with microwave directed energy weapons.

Meanwhile, gun launderer Drebin 893 provided his services to the Missouri ' s military personnel, issuing them with "naked" weapons, along with catapults that the strike team would be using.

"At Dawn"
"Failure will spell doom for the human race."

- Roy Campbell via Codec

As the Missouri closed the distance to Outer Haven, Snake (carrying Otacon's Mk.III), Meryl, and Johnny, prepared to board the enemy ship. Commencing fire to defend against Haven's missile barrage and deployed Metal Gear RAY units, the Missouri collided into the other vessel, plowing along its side. The strike team then activated their catapults and ascended upwards onto Haven, though Johnny hit the side of the ship and fell into the ocean. Meryl landed in a different area of the ship than planned, injuring her ankle, while Snake's successful jump forced him to continue the infiltration alone.

Avoiding the dense force of Gekko and Haven Troopers deployed on deck, Snake made it to an elevator on the far side of the ship, and descended into the heart of Haven. Entering a large computer control room, he was forced to take on a wave of Haven Troopers, which he ultimately defeated. Snake was then confronted by the leader of the Beauty and the Beast Unit, Screaming Mantis. Snake was able to overcome her apparent psychic abilities by suppressing his nanomachines, and then stole Mantis' mind control puppet, allowing him to defeat her. Shortly afterwards, the ghost of Psycho Mantis appeared in her place and, after making several psychic predictions, revealed himself to be the one controlling all of the BB members, through the body of Screaming Mantis. Although he prepared to attack, another spirit, that of The Sorrow, appeared and banished Mantis forever.

"No Place to Hide"
The Beauty and the Beast Unit was defeated, but Snake's mission was far from over. Continuing towards GW's server room, Meryl and Johnny appeared in time to save Snake from another wave of Haven Troopers. While Snake proceeded onwards, Meryl and Johnny stayed behind to fend off the seemingly endless supply of soldiers, eventually running low on ammunition. In the heat of battle, Johnny proposed to Meryl, claiming he had always loved her. Initially, Meryl refuses his proposal. Since she always wants to do things her way, she herself proposes to Johnny, who gladly accepts.

Snake was then further outnumbered by knife-wielding Haven troops, who ambushed him directly outside the microwave corridor leading to the server room. A still armless Raiden then appeared to protect him, requesting that he upload the virus himself, as his body could withstand the microwave emitters. However, Snake refused, with Raiden relenting after further argument. Allowing Snake to pass, Raiden decided to keep the encroaching enemy soldiers away. However, the battle was still heavily one-sided, and Raiden, although initially fighting well, was quickly swarmed and outnumbered.

Snake entered the microwave corridor, and with no other choice available, began to make his way past the powerful emitters. Forced to walk due the immense pain, he eventually collapsed and forced himself to crawl the remaining distance, growing weaker every second. His OctoCamo was stripped from his skin and his Solid Eye exploded from the waves. However, against all odds, he made it to the server room, where the Metal Gear Mk.III uploaded the virus, just as Snake was swarmed by an army of Dwarf Gekko.

"Full Circle"
With the successful upload of the worm, the battle quickly turned. The soldiers ambushing Raiden, Meryl and Johnny went into hysterics as their nanomachines shut down, and the Dwarf Gekko surrounding Snake deactivated. The unmanned RAY units attacking the Missouri also shut down, with some sinking into the ocean depths.

Shortly thereafter, a video of Naomi Hunter, programmed into the worm, appeared on the server room computer screens. She explained that the worm, named FOXALIVE, had used GW as a conduit into the Patriots' entire network, destroying the AI cores, disabling SOP, and bringing the war economy to a halt. The Patriots had apparently intended to extend their nanomachine control to the civilian population, and she had been unwilling to allow this. Having intentionally misled Snake and Otacon into carrying this out, Naomi apologized for her deception. Exhausted, Snake collapsed into unconsciousness.

"The war is over. But we've still got a score to settle."

- Liquid Ocelot seeking one last fight with Solid Snake

Liquid Ocelot found Snake, while Otacon had gone to find medical help, and dragged him to the top of Outer Haven. Explaining to Snake that the worm's upload had been his intention all along, as well as the history of the Philosophers and the war between Zero and Big Boss, Liquid proclaimed that Big Boss's dream of Outer Heaven had come to pass. Challenging Snake to a final hand-to-hand duel, he restored his brother's stamina with an injection, then engaged him in CQC. During the fight, Revolver Ocelot's psyche began to emerge, displacing his Liquid persona. Upon being defeated by Snake, Ocelot stated that he was "Liquid's doppelgänger," and exclaimed "You're pretty good," before dying.

Otacon later discovered that Sunny had modified the FOXALIVE worm to "destroy the brain, but leave the brain stem intact." Rather than destroying the Patriots' system entirely and plunging the world into chaos, Sunny had programmed the worm to remove their control while preserving the energy and resource networks essential to modern society, allowing the U.S. to truly live free for the first time in many years.

Behind the scenes
"Old Sun" is the name of Act 5 in Metal Gear Solid 4: Guns of the Patriots.

As in the other acts, trading "Sun" for "Snake" forms a codename. In this event, it is Old Snake, Solid Snake after his accelerated aging.

The scene in which Solid Snake has to traverse a microwave tunnel on board Outer Haven, shares similarities to the final scenes of the original Metal Gear. In Outer Heaven, Snake is forced to pass over an electrified floor, while his life gauge steadily depletes, in order to reach TX-55 Metal Gear.

During the montage in Liquid Ocelot's explaination about the history of the war between the Patriots and Outer Heaven, a missile was seen firing upwards and hitting the satellite with JD.