Solid Snake, the formerly retired FOXHOUND agent returns as the playable character. His new mission is to rescue the kidnapped Czechoslovakian biologist, Dr. Kio Marv, from the forces of Zanzibar Land. He is assisted by a radio support crew consisting of Roy Campbell, his new commanding officer; McDonnell Miller, a survival coach and drill instructor; George Kessler, a military strategist; and Johan Jacobsen (Yozef Norden in the original MSX2 version), a wildlife expert. Also assisting him on-site are Holly White, a CIA agent posing as a journalist; Gustava Heffner (Natasha Marcova in the MSX2 version), an StB agent and Dr. Marv's bodyguard; and Dr. Drago Pettrovich Madnar, the Metal Gear designer from the first game, who was captured along with Dr. Marv. Also appearing in the game are Big Boss, FOXHOUND's commander-turned-traitor from the first game; and Gray Fox, who disappeared following the events of the first game.

The bosses of this installment consist of Black Ninja (Black Color in the MSX2 version), an experimental drug-enhanced soldier (who is revealed to be Schneider from the original Metal Gear); Running Man, an agile mercenary; Red Blaster, a grenade throwing expert; the Four Horsemen (Ultrabox in the MSX2 version), an assassination squad specializing in confined spaces; Jungle Evil (Predator in the MSX2 version), a jungle warfare expert; and Night Fright (Night Sight in the MSX2 version), an assassin who uses a state of the art stealth suit that renders him invisible.

[edit] Story

By 1999, the Cold War had thawed, and nuclear disarmament by the major world powers promised a bright beginning to the 21st century. Despite this, all was not well in the world. A series of shocks to the oil market spurred the development of new high-tech energy sources, including fusion power. However, most vehicles still relied on oil for power.

Oil reserves were at a critical low, and the world community was prepared to take drastic measures, either by drilling into sand and shale for more oil, despite the difficulty -- or moving on to renewable fuels.

Such steps proved unnecessary when Czech scientist, Dr. Kio Marv, successfully bio-engineered a new species of algae, OILIX, that could produce petroleum-grade hydrocarbons with little expense and effort. Marv presented the algae to the World Energy Conference in Prague, and was on his way to a demonstration in the United States when he was kidnapped by soldiers from Zanzibar Land. NATO discovers that Zanzibar Land's leaders plan to hold the world hostage by controlling the supply of oil and nuclear brinksmanship, via a stockpile of nukes raided from nearby missile sites.

Solid Snake is brought out of retirement by FOXHOUND's new commander, Roy Campbell, and is sent to Zanzibar Land to rescue Dr. Marv.

On the course of his mission, Snake teams up with Holly White, a CIA operative posing as a journalist, and Gustava Heffner, an StB agent and Dr. Marv's bodyguard. He is also reunited with Dr. Drago Pettrovich Madnar, the Metal Gear inventor from Outer Heaven, who claims to have been once again kidnapped and forced to work on another Metal Gear project (named Metal Gear D) for Zanzibar Land, as well as oversee mass-production of smaller, non-nuclear-equipped Metal Gear units. Snake learns from Dr. Madnar that Big Boss, Snake's former FOXHOUND commander, has survived and is the man in charge in Zanzibar Land.

Upon reaching the suspension bridge leading to the Detention Camp, Gustava is killed by a missile fired by Metal Gear D and Dr. Madnar is recaptured by the enemy. The new Metal Gear's pilot is revealed to be none other than Snake's former mercenary buddy Gray Fox. Determined to finish his mission, Snake fights against Zanzibar Land's elite mercenary force and manages to reach Dr. Marv's cell.

Snake arrives too late, unfortunately, as he finds the corpse of Dr. Marv, who was unable to survive the repeated torture. Dr. Madnar is also there and explains he was unable to save him. Just before Snake could retrieve the OILIX formula left by Dr. Marv, Holly reveals via a radio message that Dr. Madnar was not captured after all, but voluntarily resumed his work on Metal Gear and was personally overseeing its development as a result of being rejected by the scientific community after the Outer Heaven incident. After the truth comes out, Dr. Madnar attacks Snake, but fails in killing him.

With the OILIX formula in Snake's hands, Snake is confronted by Gray Fox piloting Metal Gear D. After successfully destroying Metal Gear D, Snake finds himself in a minefield. The two engage in hand-to-hand combat against each other, and Snake eventually emerges as the victor.

Upon defeating Fox and retrieving the OILIX formula, Snake is met by Big Boss while trying to escape. Having lost his equipment and with no weapons at his disposal, Snake is forced to improvise using the only items he can find, a lighter and aerosol can. Fashioning a makeshift flamethrower, Snake defeats Big Boss for the second time. Snake and Holly escape together, and they deliver the OILIX formula to Campbell.