Walk into the clearing. Go to the furthest left ?. It should be the wreck. Once you are inside the wreck, pull on the hanging wire. A ghost will appear and leave you a engraved rod. Pick it up. Next open the chest and take the device inside. Oh, you better pick up the wire too. Now you can leave the wreck and go to either one of the remaining two ? locations.
Slope- Use the device. When Boston says "It's pointing at this mound", use your shovel with the mound. Pick up the bracelet that you find.
Graveyard- Pick up the loose tusk and use the shovel with bone pile. Pick up the uncovered jaw bone.
After you have completed all of the above, go back to the dais. A ghost will appear and show you where to dig. After you dig for awhile, Brink will eventually take over. He will fall down the hole and die. Don't worry about his body, you can't do anything with it now.
