“We already know they used the table of elements to devise the clues. Now, the four cardinal directions each corresponds to one of the original four elements of the ancients. We've already gone through water---the waterfall, fire---the Hall of Fire, then we had to swing through the air. That only leaves the element of earth. Which corresponds to... north." She looked up from the compass to the door ahead of them.
He stared at her in admiration "You're good."
"Maybe it's just my Promethean blood.”