zzZombie

Check out this thread. Answers everything for you. http://callofdutyzombies.com/forum/viewtopic.php?f=72&t=16211

Definitely not the end of zombies. Just a great cliff hanger. Not sure why no music would mean the end. I figured it went with the lack of sound in space.

No Man's Land is at Area 51, Hanger 18 to be exact. You start there and need to teleport to the moon. When you start the zombies are already spawning and pressing you. I think the separate leaderboard and timer is due to how hard it is. Endless waves of insane, running zombies, and dogs.

Do yourself a favor and hold off watching videos. There are so many cool things that would probably be better experienced for the first time without any prior knowledge.

The growl happens when the power is turned on. And it does sound like it's coming from the ceiling of the theater.