Larian Studios Forums Divine Divinity (English) Help/Tips/Tricks completed quest reappeared. in quest book

I can't even complete this quest. Well, I did everything. But I can't get the 'reward' from Marcus.

I didn't go to Verdistis until after finding Pedro's note and locating the cave. Is there anyway to 'learn' the identify skill now? I really don't want to go back..