Kill Jarko (yourself) (beware he is strong), and take his Book of Spells.

Take the book to Araknor, northwest of the temple of Lighthaven, saying the word grimoire.

You can complete this quest at will.

Gain:

• 300 gold coins
• Ring of Darkness or Ring of Confidence
• You become the apprentice of Araknor the Necromancer (unlocks The Blind's spells on Raven's Dust)