Stuck in Overature, Ch 3

[iliaarpad]

I also happen to have the blank note but the door to the refinery seems to be closed. I've already been there. I know what to do with the blank note, my problem is that I first went to the refinery (without the note) and then went to shaft 13 (where I happened across a blank note). Anything I could do?

Edit: Never mind, I was looking for THAT room in the wrong place, sorry.