Ok here is my theory. If you look at the description of the map Discovery it says ''Unlock the mysteries of this abandoned german research station in Antarctica''. Now why would it say ''Unlock the Mysteries''.All the other maps say small map good for objectives that sort of thing but this says unlock the mysteries??? And if you look there is a power box in discovery just like in other zombie maps where u turn on power and if you remember in the campaign there is one mission where you have to defend the Nova 6 from the british and russians so maybe the british got hold of the nova 6 and made their own zombies???
