This guide is suitable for current RuneScape and Old School.
Treasure Behind the Falls
To start, talk to Almera in the house at the top of the Baxtorian falls. She will ask if you can help find her son, Hudon, who has gone missing after riding downriver on a raft.
When you accept, go out the back of the house and climb aboard the raft waiting there. You will be thrown off on a small island. Shout over the river at Hudon, who is waiting on the riverside. He will refuse to come home before finding buried treasure he claims is located behind the waterfall.
Click on the water, and swim into it. You will wash up futher downstream. Go into the house slighly north of your new position. Go upstairs, and search the bookcases until you find a 'Book on Baxtorian'. Read through it (you don't actually have to read it, just skim through the pages). Talk to the person downstairs, and ask all the options.
Gathering the Items
Go to the Tree Gnome Village, and make your way through the maze, or get transported to the center, whichever you can do fastest. Just outside the entrance to the village itself, in the area with the level 5 goblin, there is a trapdoor. Climb down it into the cavern below, full of Hobgoblins. Search the crates in the area to the east, until you find a key. Go to the far western room, and open the door. Walk through and talk to Golrie. He will take the key off you, and give you Glarial's Pebble.
Remove all armour, weapons, and runes, and go to the area east of the house where you found the Book on Baxtorian. Use the pebble with Glarial's Tomb. If nothing happens, then you still have an item that you cannot take into the room.
You will find yourself in an underground cavern. Run west, past the Moss Giants, and open the chest to get Glarial's Amulet. Run back a bit, and then go south. Search Glarial's Tomb, and you will get an urn. Go back to the ladder and exit the tomb.
Into the Falls
Get the 6 air, earth, and water runes, the amulet and urn, and any armour and food you might need. Go back to the house at the top of the falls, and board the raft once more. When you arrive at the island, use the rope with the rock on the island with the option 'swim to'.
You will haul yourself over there. Use the rope with the tree, and you will climb down onto the ledge.
Open the door and go through.
Once inside, run north-east, into the room with the skeleton mages, and search the crates for a key. Once you have it, run into the far western cavern, and run past the level 122 fire giants. Use the key to unlock both doors. You will be in a room with 6 pedestals and a large chalice floating in the air.
Use one of each type of elemental rune on each of the pedestals. Once you have done that, use the Glarial's Amulet on the statue of Glarial. The floor will rise up to the height of the chalice.
DO NOT TAKE THE TREASURE FROM THE CHALICE. If you do, the entire cavern will flood. Instead, use the urn with the chalice.
Congratulations! Quest Complete!
Guide Made by: Deathslayer
Corrections submitted by: DaDa, Simon, Anita, Vanilla990, Majinvegito3, Power of Five, Valerie, Tiny, Riot Games