Enter the Vestibule by clicking the boulder where Kaira was. Mobs inside are Vestibule defenders (may be non-aggro if you've never gained their hate by killing any of the winged maidens outside), frosty pests, and frosted bubbles. Mobs range from L60-63 (for a L72) There are three clear globes which are the Sacred Vessels in the cave: one to the right, left, and behind The Guardian. Head forward across the bridge to The Guardian and speak to her. She gives you a puzzle to solve.
Griffons fly between two towns. Every hour at precisely five minutes past, a griffon leaves each town and flies towards the other town. They all fly at the same speed and each journey takes five hours. Three of the griffons that fly this route have blue wings. Only one has red wings. How many other griffons will you see when riding a griffon from one town to the next?
The correct answer is 11. If you choose the wrong one, you fight her and still gain access to the Vessels.
Once you get access, click the Vessel where The Guardian was. Then click the Vessel to the right (the one on the left as you came into the cavern), then click the last one on the right. The keys become the Gavel of Entry.
There's a path behind where The Guardian is that leads past two mobs and to a nobleman. You can hail him but he continues to use a pick at the wall while asking why hasn't he been noticed? I don't know what he's for, I think nothing happened because of being L72 and he was grey at L50.