All quests are obtained by talking to the King in the Castle.
Initial quest text:
I need you to perform a duty for me.
Some of my clerics went to the forest in the northwest
to investigate a gathering of monsters. However, they
never came back. Go seek them. Bring back evidence
of their whereabouts. You will be rewarded.
Talking to the right cleric:
Hey! You are one of Tevon's people! What...
< While he talked, you noticed a parchment on his desk. >
< With your amazing thieving ability, you quickly snatched it. >
... are you doing here? Well, just tell that ol... Hey! Give that back!