A couple options:
- Do a life where you go the history route, go out drinking with Suzette and Jo, and pay attention to Jo so they tell you about their thesis...
OR do a run where you don't go south, go to war and get the relic, then end your life with either Suzette OR Jo as your romantic partner/best friend... they should point you in the right direction
But this is a good corner case! I'll try to write in a catch-all pathway, to point you to how to get to the stone if you've found the "best ending" without having yet been told that... Hm. I'll try to see where that fits in. You're the first one to hit this particular sequence of events, that I know of!