This is a moderate free quest in Runescape.
You need to be able to defeat a level 27 demon and some level 7 and 20 wizards if necessary.
In the city of Varrock, near the central fountain where Romeo is found, you will find a gypsy by the name of Gypsy Aris in a small tent. Give her 1 gp like she asks, listen to her story of Delrith, and Wally with his magical sword "Silverlight". She will tell you magical incantation that you say to send the demon to the hole when slayed. For every person it is different, so write it down.
She will tell you that a knight named Sir Prysin owns the magical sword "Silverlight", the only weapon capable of defeating the demon. He can be found in the Varrock palace. Talk to him and he will say that he needs 3 keys to open Silverlight from a case. He also says that he had a key, but dropped it down the drain, right outside the palace kitchen.
1st key:
Go to the drain. Try reaching the key, and like Sir Prysin, you are unable to. Now, take a bucket, fill it up with water, then use it on the drain. The key will be washed down to the sewers. To the east of the palace, right outside the walls there will be a ! sign. Climb down the hole. inside the hole, go north, turn left, go north again through the hall and you will see a drain and underneath a pile of mud. Take the rusty key from the pile.
2nd key:
Go to Captain Rovin. In the northwest corner of the castle, climb two sets of stairs and find him. He will be unwilling to listen to you, but there is a way to talk to him and make him give you the key. Don't give up, he will finally be convinced.
3rd key:
Find Wizard Traiborn in the Wizard's Tower. He tells you that you need 25 sets of bones to reach the key in his closet. Get the bones and give them to him. He will give you the key.
Come back to Sir Prysin. He will open up the case and give you Silverlight. Go to the stone circle beneath Varrock. With Silverlight in your hand, approach it. Fight the demon and maybe some wizards.Then say the magical phrase you wrote down earlier and make the demon disappear back into his hole. The quest is then finished.
