A former NSA codebreaker, one of two who defected to the Soviet Union in a notorious 1960 incident. The other defector was EVA (not the same EVA that appears in the story).

At the time of Operation Snake Eater in 1964, ADAM was dispatched as a spy by the Soviet KGB to provide aid to the American agent infiltrating the country. However, ADAM failed to make contact with the agent, Naked Snake, and EVA was sent to make contact with him instead.

The woman calling herself EVA at Groznyj Grad was actually a spy for Communist China. The KGB man calling himself ADAM was in reality Adamska (Ocelot), who was simultaneously spying for both the Soviet KGB and the American CIA.