A map of Tirannwn with relevant locationsThe starting point, with Islwyn.
Hire a charter ship for quick access to Tyras Camp. Go north through the camp, and make your way through the dense forest (56 agility is not needed this time). Go east, then south, and you will see another dense forest. Just after it are two tripwires, followed by the last dense forest to the south-east. To make sure you are in the right area, look for the tracks in the dirt from Regicide. Head north-east, pass the stick trap and continue north until you see a bridge. Do not cross the bridge. Go east from the bridge and you will see another stick trap that you will need to cross. There will be a blue quest symbol on the map.
The Roving Elves
Once inside the clearing, search the recently-extinguished remains. It will tell you that travelers are nearby, and that you should look for them. To find them, make your way back towards Tyras Camp. Pass the first 2 thickets of dense forest (need 56 agility) and you should be able to click on the white/blue clearing to the south-east of the catapult. You will pass through a stick trap.
Alternatively you could teleport to a port (such as using the Explorers ring 3 or the Port Sarim Lodestone to go to Port Sarim) and then take another charter ship to Tyras Camp.
If the two elves are not there, wait a few minutes for them to come back (or hop worlds). Speak to Islwyn first. He will tell you he is not fond of humans because they opened the tomb of his grandmother, Glarial. Tell him it was you who opened it, and offer to help him put his grandmother's soul to rest once more. Speak to Eluned, who will tell you that the tomb of Glarial will need to be consecrated.
Note: If you don't have Glarial's Amulet, you can get one by searching the chest at the north end of her tomb. If you don't have the pebble, you will need to speak with Golrie, who is in the dungeon next to Elkoy in Tree Gnome Village.
Glarial's tombGo to the Ardougne bank and store all weapons, armour and runes in the bank. Withdraw the above items. You are going to have to fight a level 84 Moss giant without any armour, weapons, runes or prayer.
Run north from Ardougne to Glarial's Tomb, which is north-west of the Fishing Guild. You can also teleport to the Fishing Guild using a skills necklace. Use Glarial's pebble with the tomb, and if you do not have any items in your inventory that are forbidden, the tomb will open. Once inside the tomb, you will need to find and defeat one of the level 84 Moss giants. Prayer does not work here. If you have completed the quest, Lost City, you may bring a knife and dramen branch to construct a dramen staff when inside the dungeon. Once the Moss Giant is dead, take the Consecration seed it will drop. Take the seed quickly, as the Moss Giant will respawn relatively soon and attack you, or the other one will.
Note: Be sure to kill the moss giant next to Glarial's tomb (the gravestone in the grassy area), as the other moss giants are unlikely to drop the seed, however they can.
Note: There is a slight chance to receive the seed from killing a moss giant that isnt near Glarial's gravestone. The one in front of you when you go into the cave may work. if you don't want to risk it, follow the note above.
Note: You may not obtain the seed at first so its a good idea to have multiple sets of food in bank.
If you don't remember how to get inside the tomb from the Waterfall quest, follow these steps:
Go through the house to the backyard. You will see a raft.
Board the raft to get down the river. You will crash halfway.
Do notuse the "swim" option. Instead, use your rope on the rock to get to the next island.
Do not climb, but rather, use your rope on the dead tree there to get down to the entrance.
Enter the dungeon
Planting the seed
Planting the Consecration seed
If you don't have A key (Waterfall Dungeon), first take the path to the eastern room. Go to the crates located the furthest to the north. Search them to find the key. Now go back to the main room.
Go west. Run past the fire giants to a locked door. Use your key on it to get through.
Use the key on the next door to the north.
Left-click the seed ("Plant"), you can do this anywhere in the room.
Time to report back to Islwyn and Eluned. Teleport to Port Sarim and charter a ship back to Port Tyras.
Ending
Go back to Islwyn to claim your reward. Pick either a crystal bow or a crystal shield. Both can be bought later; the bow for 900k coins and the shield for 750k.
If you begin talking to Islwyn or Eluned and they teleport while you are in conversation, as long as you do not leave the conversation (move, open a skill interface etc.) you can finish the conversation.
When you enter Baxtorian's tomb and you're outside the tomb, you see the floating cup but the rings that came up to make stairs appear to be flat like they were before you put it there. When you enter the room it goes back to popped up into the stairs.
At one point, if you had an item considered as a weapon in your toolbelt, you would not be able to continue. This glitch has since been fixed.
When chosing your crystal bow or shield, the option for the shield is "Give me a shield, I'm tired of hiding behind mushrooms. This may be a reference to The Lost City quest where many people use mushrooms as safespots to kill the dramen spirit.