Solution

On the center path, solve the scales puzzle (Helm + Fruit), then choose Thal.

Description

“Sil'dih aqueducts. Thorne. Vault.” I noticed these words scribbled on the back of the burglar's note we found, but was too preoccupied to give them much thought at the time. Did the intruder believe that a secret cache of Thorne riches was to be found somewhere in the waterways? An odd notion, given that the House of Thorne was well known for its honesty and integrity. After all, 'twas a sultan of their dynasty who willingly transferred power back to the House of Ul, and there was nary a peep to imply any wrongful withdrawals from the royal treasury. Assuming they had secreted wealth in some hidden location, it would have been done with the full cooperation of the Ul family─with the particulars passed down to successive sultans.

Father would have known of the arrangement, and he did speak of slumbering memories which should not be forgotten. Was this one of those things my parents wished me to see when I came of age?

I have considered a hundred potential scenarios for what they might have meant, each more fanciful than the last. And although the Sil'dihn palace was indeed an eye-opening discovery, I sense that Father alluded to a matter of even deeper import...