Start by talking to Mosol Rei, who is pacing around outside the entrance to Shilo Village. Ask him why you need to run, then ask who he's talking about. Ask what to do to help, and he'll ask you to go see Trufitus in Shilo Village. Agree to do so, and he'll give you a Wampum belt.
Head back north to Tai Bwo Wannai Village and find Trufitus.
Show him the belt, and ask about the legend. He will tell you of the temple of Ah Za Rhoon. Ask him more about it. Then tell him you're going to search for it.
Ah Za Rhoon
Head due east until you reach the river, then look for the log to cross. Head south along the river until you see a mound of earth.
Use your spade on it and a fissure will open up. Use your torch on it, then use your rope on it. Search it to go down. Near the little pool, look for a strange looking stone on the floor. Use your chisel on it to take it. Head to the west wall now and look for the cave-in. Search it and wiggle through.
At the first bend of the cave, look for some loose rocks on the west wall. Search them for a scroll. Continue along the cave until there is a small dead end area with a table. Search the nearby sack to find a scroll. Continue along the cave until you reach an ancient gallows. Look at the gallows, then search it and take the corpse off.
Leave however you want. One way to leave is to look for the smashed table in the first chamber. You can craft this into a raft for a quick exit. It only has a single use, so if you need to, continue along the path and search the rocks near the waterfall.
Now head back to Tai Bwo Wannai and speak with Trufitis. Ask him about Zadimus, then ask if there is any sacred ground around here. Head out the hut and look for the tribal statute. Stand next to it and bury the remains. Zadimus will appear in front of you.
You will get a bone shard back. Return to Trufitus and use the bone shard on him. Now use the stone plaque to him. He will decipher it for you. Use the scrolls on him too. After this, head to Cairn Isle.
On the very north side of the island, search the well stacked rocks. Once in the cavern, search the dolmen. Read all of the scribblings on the notes. To exit the tomb, look for the climbing rocks on the slope. Now to find her tomb.
Tomb of Rashiliyia
Look for the crossed palm trees and look for the door hidden in the hillside. Try to open it, but it will need a key. Use your chisel on the bone shard to make a bone key. Now, before entering, use your chisel on the sword hilt. Next, use the bronze wire on the bone beads.
Wear them, then use the key on the door and enter. Enter through the gate, and climb down the rocks. Head to the southwest and look for the tomb doors. Carefully use the bones on the doors. When it's complete, enter the doors.
Try looking at the dolmen. Nazastarool will appear and fight you. Defeat his zombie form, and he will reanimate into a skeleton. Defeat him again, and he will appear as a ghost. Defeat him a final time, and Rshiliyia's corpse will appear on the dolmen. Take it.
Rest In Peace
Return to Cairn Isle now, and return to her son's tomb. Use her remains on the dolmen, and she will thank you.