This guide is suitable for current RuneScape and Old School.
Speak to King Arthur who can be found within Camelot castle.
Ask him about joining the Knights of the Round Table and he will tell you that he has a quest for you. Somehow Merlin has been cursed and become trapped inside of a crystal and King Arthur will ask you to set him free. Speak to Sir Gawain and ask him if he has any ideas how Merlin got trapped inside the castle. Sir Gawain will tell you of Keep le Faye but will have no idea how to get there. Head over to Sir Lancelot (on the second floor) and he will tell you that he knows somebody in Catherby who will be able to take you to Keep le Faye.
Getting into Keep Le Faye
Make your way to Catherby and by the docks you will find a man called Arhein. Ask him if his ship goes to Keep le Faye and he will inform you that it does but he cannot give you a ride as Sir Mordred isn't fond of strangers inside his keep.
By the candle shop you will see a small crate. Climb inside and you will be transported to the keep disguised as candle supplies.
Enter Keep le Faye and go to the third floor where you will find Sir Mordred. Fight with him until he is close to dying, and his mother Morgan Le Faye will appear asking you to spare her sons life. You will agree to under one condition; she tells you how to free Merlin from the crystal. She will explain that you'll need bat bones, a black candle and Excalibur and will have to recite the magical words under the Chaos alter in Varrock.
Collecting the ingredients for the spell
If you don't already have some bat bones, exit the keep and kill a bat outside. Then return to Catherby and enter the candle shop. Ask the candlemaker if he can make you a black candle, and he will ask you to get some wax from the beehives. Behind the bank in Catherby is a house with some insect repellent, go and take some and then head to the beehives to the west. Use the repellent with the beehives and then use a bucket on the beehive to collect the wax.
Take this back to the candlemaker and he will make you a black candle.
Now head to the peninsula south-east of Taverley, and speak to the Lady of the Lake. She will tell you that Excalibur can be found within the jewellery shop in Port Sarim. Make your way there and you'll see a beggar outside, who will ask you for bread. Upon giving the beggar the bread, he will transform into the Lady of the Lake who will say that you have passed her test and present you with excalibur.
Make your way to Varrock, and in the south east you will find the Chaos altar. Check the altar and you will find the magical words, Snarthon Candtrick Termanto
Return to Camelot and head to the northeast side of the grounds and you will see a circle of pillars. Drop the bat bones within the circle and a spirit will appear. Recite the magical words to the spirit and ask it to free Merlin.
Note: if you don't tell the spirit the correct words, it will transform into Thrantax the Mighty (level 92) and attack you.
Finally, go the third floor of Camelot castle on the southeast tower where you find Merlin. Shatter the crystal with Excalibur and he will be freed. Return to King Arthur.
Congratulations! Quest Complete!
Guide Made by: DaDa
Corrections submitted by: Doctor Shemp, DaDa, Dx1438, Power of Five