A new quest

Well, after talking with a bunch of elves in the town and the castle I find out that the Elf Prince has fallen under a curse. Astos, the king of the Dark Elves stormed the castle, cursed the prince, and then stole all of the treasure. Heck of a security force, huh?

Everyone is sad because the prince was meant to be the next king and clearly the whole nation cannot continue without him. Instead of picking someone else to be king they have decided to languish and concede their nation to the dark elves.

A few hints as to what I need to do popped up:
No one knows where Astos has gone.
There is a witch who makes potions.
Someone came across a spooky castle, but was so scared that they ran off.

Well, sounds like I need to find the castle, beat Astos, and then find the eye so I can talk Matoya into making a potion for the prince. Sound like a plan?