Highstakes

Hey,.. I did the Waterfall quest, but i figured I didnt need any of the items any more. So I dropped them, but now I need them for Roving Elves!!!! I dropped Glarial's amulet and urn. I also dropped Glarial's pebble,.. but I know how to get that back. I need help in getting the items back. Or if i even need them for the quest.