Curt, Dana, and Holden are trying to flee the cabin on the Rambler by going back through the tunnel; it's supposed to have been collapsed by now but Demolitions had a little glitch and the tunnel was still open. Fast-forward to when everyone is celebrating because they think the ritual is over. Sitterson comes over to Demolitions and is talking to them about what happened and they say
DEMO #2 : No, seriously. That wasn't on us. There was an unauthorized power re-route from upstairs.
Sitterson stops mid-drink, frowns. Wait —
SITTERSON : What do you mean, "upstairs"?
Sitterson becomes very serious and concerned but the red phone rings and we don't get anymore info from Demolitions.
So, who is "upstairs"? And why would they (seemingly) want to let the kids escape if they know that this would lead to the DESTRUCTION OF THE WORLD!?