Go to the first area where you found Chance. That should be right beside a "WATERFALL". Go to the edge of the waterfall. Make sure you are on the side that Chance was/is on. Now turn around drop down and grab the edge that you were on. Now you should be hanging OVER A HOLE. IF NOT ALIGN YOURSELF TO WHERE YOU ARE. Finaly drop down. You should be standing in a cave. Inside you will find The H-11.(To get out just simply go to the edge of the cave and face the other side of of the waterfall, now turn around and jump up.