I think I know what happened; I did things in a sequence the game didn't expect, I guess.
I took the archive by myself before talking to Ruth. I killed everyone at the entrance, pickpocketed the calcaduceus from the guy in the bathroom, and spoke with the archive. He triggered the quest to fix the things in the underlands, and only then I spoke with Ruth, took over Spiretown, and fixed the archive fully. Now the objective to deliver the calcaduceus to the order is active, but there are no order members at the archive to talk to and give the damn thing to. Somewhere along all that, the game forgot to spawn the order members at the archive. This all started because I wanted to see if Ruth had an interaction for me, for already having the calcaduceus when I talked to her. She doesn't ;_;
