You find a letter beside the bed:

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"Tomorrow is the big day. We're taking a crew to explore the place Julie found. She says there is grass and trees and everything! I'm hopeing the stress hasn't gotten to her. We've all been a bit delusional lately. But if she's right this might just be the thing we need to ease our minds a bit.

There is a chance I won't return, so since you'll be in charge if I don't, I wanted to let you know where the vault is. There is a lever under the desk in the Assembly Room that opens the vault. I have always used that place as my office, so it will be yours if I do not return."