Lost to the mysts of time and catastrophe, the fabled Zhao Zwehian Library has reappeared. Or at least, part of it has...
"The wind-driven snow parts for the barest of seconds, revealing a glimpse of refuge from the deadly storm. It’s a massive sapphire pyramid. Yet you know of nothing like it in this area…"
The PCs see a large oak tree, a curious species of yellow and black butterflies swarm around it. Upon further inspection they find that the tree is hollow and that there is an underground cave in it from which the butterflies appear. Will they inspect this strange cave?