The first Metal Gear Solid released on the Playstation Console

The Story
The peace foretold by Metal Gear 2 never came to pass, and by 2010, nuclear deployment was again in full swing. A United States military installation on Alaska's Shadow Moses Island, while playing host to a series of tests involving a new secret weapon, was hijacked by a group of terrorists. Interestingly, the group was led by renegade agents of Fox Hound, Solid Snake's old unit. Important government and corporate officials were on hand to observe the tests, and they were taken hostage. The terrorists' demands were simple, if a bit puzzling: They wanted the remains of Big Boss within 24 hours, or a nuclear warhead would be launched. Former Fox Hound commander Roy Campbell calls on Solid Snake to infiltrate the base, rescue the hostages, and disable the terrorists' nuclear capability.

Snake was shocked to find out that the leader of the insurgence is Liquid Snake, an agent with the same codename as him and almost identical physical features. Joining Liquid was a group of Fox Hound's top agents, such as gunslinging torture specialist Revolver Ocelot and perceptive powerhouse Psycho Mantis. Vulcan Raven, Sniper Wolf, and Decoy Octopus rounded out the crew. Liquid Snake also commanded a legion of genome soldiers, troops whose genes had been conditioned to increase their physical attributes. In light of this capability to manipulate genes, the terrorists' demand for the remains of Big Boss, the "legendary soldier," became understandable.

Snake successfully breached the base's security and found the hostages, and from them he learned that the tests being conducted on the island were for a new model of Metal Gear, called Rex. Snake's mission then became one of search and destroy. En route to Metal Gear, he encountered a number of interesting figures, including Meryl Silverburgh, niece of Roy Campbell and inexperienced soldier, and Hal Emmerich, aka Otacon, the lead scientist on the Metal Gear Rex project. Snake and the terrorists were also stalked by a mysterious cyborg ninja who was later revealed to be the previously deceased Grey Fox.

After defeating all of the Fox Hound agents (except Revolver Ocelot, who escaped), Snake destroyed Rex. Liquid Snake then confronted him and revealed a terrible secret about their lineage. Both of them were genetic experiments, born of the "Les Enfants Terribles" (the terrible children) project in a laboratory and crafted by scientists from the genetic material of Big Boss, known as the perfect soldier. Despite his emotions to the contrary, Solid Snake exists solely to fight. After a narrow escape and the apparent death of Liquid, Snake and Meryl rode off once again into the sunset.

After the credits roll, we hear a brief transmission from the sole Fox Hound escapee Revolver Ocelot to, of all people, the president of the United States. It appears that Ocelot was a double agent the whole time, and even more shockingly, that Solidus, the president, was a third product of Les Enfants Terribles. What this portends for Solid Snake's future remains to be seen, but you can bet that it's not good.

Source: Gamespot History of Metal Gear