The Vast Treasures of the Old Necromancer   

The group of islands in the middle of the ocean was a distance away from the Ferde Wilderness. If Celine had to make two 380 miles' roundabout trip to ferry them back to camp, she would definitely be drained of her energy. Luckily, there was a group of wild Griffins on the island.

They grabbed a Griffin each after intimidating them with their powers and commanded them to fly back in the direction of the mainland. 

The Griffins were fast. Within two hours, the three of them once again arrived at the entrance of the underground palace. The moment the three Griffins regained their freedom, they flew off immediately, looking clearly startled and in fear. They then proceeded all the way into the deepest area of the underground palace

without any obstructions.  

Vance carefully observed the furniture in the underground palace and said in disbelief,