Lore

In the aftermath of World War II, the victorious powers secretly split a fortune amassed by a pre-war intelligence network known as The Philosophers. That hidden fund — the Philosophers' Legacy — became the shadow currency funding covert operations on both sides of the Cold War.

The Boss, a legendary American soldier and the founder of CQC (Close Quarters Combat), fought alongside her student Naked Snake during the Cuban Missile Crisis, and the two are considered the finest soldiers the U.S. has ever produced. In 1964, with Cold War tensions at a boiling point, the CIA's Colonel Roy Campbell recruits Snake for a solo deniable mission into Soviet territory.

Snake infiltrates the Soviet wilderness to extract Soviet weapons designer Nikolai Sokolov, creator of the Shagohod prototype, before the GRU can weaponize his research. The extraction succeeds, but at the ruins of Rassvet, The Boss defects to the USSR, siding with the rogue GRU colonel Yevgeny Borisovitch Volgin. She executes the American ambassador and detonates a stolen tactical nuke on Soviet soil, framing the United States for the strike. Snake is shot by his own mentor and left for dead in the river below the Dolinovodno bridge.

Weeks later, having survived his wounds, Snake re-enters the same jungle under a new codename: Snake Eater. His orders are absolute — assassinate The Boss, recover Sokolov a second time, and destroy the Shagohod, a nuclear-capable walking tank Volgin intends to use to seize power within the Soviet military. Along the way, Snake is supported by the mysterious spy EVA and the young GRU major Revolver Ocelot, and is hunted by The Boss's own elite unit of legendary soldiers: Cobra Unit — The Pain, The Fear, The End, The Fury, and The Sorrow.

Snake infiltrates Volgin's fortress at Groznyj Grad, is captured and tortured, and escapes to sabotage the Shagohod before it can become operational. After defeating Volgin in single combat and destroying the Shagohod with an RPG-7, Snake finally confronts The Boss in a field of white flowers. Their duel is both a physical fight and an emotional reckoning between master and student. Snake wins, and learns only afterward that The Boss's defection was itself a mission — ordered by the U.S. government to recover the Philosophers' Legacy and preserve deniability — making her death, at his hands, the price of peace between the two superpowers.

In recognition of completing the mission and executing his mentor under orders, Snake is awarded The Boss's title and decorated as Big Boss. Deeply shaken by what he was made to do, he goes on to found the private military company FOXHOUND, planting the seeds for the conflicts that will define the rest of the Metal Gear saga.