In the aftermath of the events of Ground Zeroes and the destruction of Militaires Sans Frontières, Big Boss falls into a coma. Nine years later, he awakes and forms a new mercenary group, the Diamond Dogs. Now under the guise of the codename Venom Snake, he ventures into Afghanistan during the Soviet war to track down the men responsible for MSFs destruction. Along the way, he becomes reacquainted with his former rival Ocelot and encounters a unit of warriors robbed of their past, present and future. While he and Kazuhira Kaz Miller are initially driven to exact revenge, Snake soon unearths a plot by the Cipher organization to develop a weapon with the potential to surpass even the Metal Gear system, and his mission quickly switches focus to ending this new threat.