(Warning: When we say 'secret', we mean it. To avoid spoilers, look away now). It sounds like the start of a Cold War-era gag. But it's not.
US Presidents John F. Kennedy and Richard Nixon are in the Pentagon, discussing the aftermath of the Cuban Missile Crisis with Fidel Castro. US Secretary of Defense, Robert McNamara is lurking in the background.
The doors fling open, and hordes of zombies pour in. The tension in the room is lifted, as North American and South American, Commie and Capitalist, join arms in battling the horrific undead.
Not a lead-up to a punch-line - but a real level from CoD: Black Ops. The stage was shown in a video leaked online today, which has been hastily deleted by Activision.
The setting is thought to be a reward for completing the single-player game, and becomes even more farcical than the description above suggests.
When the zombies attack, Kennedy reveals a hidden stash of weapons and jokes: "Gentleman, lock and load."
Call Of Duty just got a sense of humour. Sounds brilliant.
The game is due out worldwide on November 9 for the PC, Playstation 3, Xbox 360 and Wii.