The 1981 Mount Yamantau raid occurred on 3 March 1981 when a team of American CIA "Black Ops" operatives inserted into the Ural Mountains of the Soviet Union's Russian SFSR to steal the computer mainframe from the destroyed Soviet base at Mount Yamantau before the Soviet spymaster Perseus could salvage it.
As part of his plan to bring about a world revolution against the United States and its allied regimes, Perseus planned to trigger a series of nuclear explosions in European capitals utilizing America's "Operation Greenlight" arsenal, which would damage European public opinion of the United States and allow for Perseus and Vadim Rudnik's sleeper agents to engineer communist seizures of power in Western Europe and isolate the United States. In order to protect the identities of the sleeper cells cultivated by Nikita Dragovich during Project Nova in the 1960s, Perseus initiated an operation to salvage the old mainframe at Mount Yamantau to erase the names of Dragovich's sleeper agents. The Americans learned of this excavation after stealing computerized files from a Soviet base in the Ukrainian SSR, and their insider within the KGB, Dimitri Belikov, confirmed an active operation. CIA agent Jason Hudson sent Alex Mason and Frank Woods to find the mainframe before Perseus did, and Belikov flew the agents in on a chopper in exchange for an American baseball cap.
The Americans initially used stealth to infiltrate the ruined base, using silenced weapons to take out Soviet patrols. Three Russian patrols were wiped out before the Americans located the old SATCOM building, and the two of them zip-lined down a cable and entered the building, where they collected evidence from Operation Red Circus before overhearing Russian voices over the radio reporting that the crane was nearly ready at dig site seven. Woods and Mason decided to search for the crane to find the mainframe, and they proceeded to engage in open combat with the Russians on their way to the dig site. Even though they were briefly separated, the two CIA operatives made their way to the crane, which hung right over the atrium and within spitting distance of the old computer room. Woods radioed in to Belikov, ordering him to return with his helicopter and have his winch ready so that the Americans could leave the base with the entire mainframe unit in tow. With ten minutes' time before the helicopter returned, the Americans cleared the dig site of Soviets, and they killed every Soviet soldier they encountered on the way through to the crane. When Belikov's helicopter arrived above the chasm, the Americans hooked the cable to the mainframe unit, and the Americans were lifted up from the chasm aboard the unit while using machine-guns to mow down the Soviet soldiers who attempted to shoot the fleeing Americans. Belikov flew out of the Urals with his operatives and the mainframe in tow, and the CIA was disappointed to discover that Perseus had deleted the names of the sleeper agents Dragovich had used in 1968.