(adsbygoogle = window.adsbygoogle || []).push({}); If you open the main room, (On the Stage) , there are two ladders. If you face the mystery box, look to the the left and then up. There is a ladder too high to jump on, and at the top a platform to walk on. If you look along it, there is also a Door up there, one that looks like it could be opened.
My theory is, the door leads to some sort of switch to open a bigger door for the thing on the roof, maybe a boss. To see this, look forward at the mystery box on the stage, and look straight up. There are two massive doors and wood boarded up on them. I think "The boss" , if there is one, is the Little Girl, since at the beginning if you play Zombies solo, the Doctor says "...I wonder what happened to that little girl...". Also, one of the secret rooms after the Pack-a-Punch contains a massive teddy. Massive teddy = Massive little girl?
It could also be the Cosmic Silver-back from Dead Ops, but i'm more convinced by the little girl.
If anyone is good at using a jump boost given by a crawler, check it out yourself, or add me on Xbox LIVE to do it.
Discuss what you think.

~Animated JoeJoe