When you enter the ghost ship for the first time in the northwestern sea (after you have collected all three spirits, Power, Wisdom, and Courage) go down the stairs. Defeat the enemies. The blue flame will extinguish. Talk to the girl in red. She will ask you to find her three sisters (one on each floor). When you find the girl in yellow (the second sister you will find), she will say that there are two treasure chests. Insist to take the one on the left. She will ask if you know which one is left. If you select "Not really" she will say "You silly boy, left is the one that isn't right". If you take the one on the left you will get a ten Rupoor, another Reapling will appear, and the girl will laugh and say "TEE-HEE! how unlucky for you."