Reward: | 3 Quest Points, Silverlight Sword

Talk to the Gypsy in the Varrock town square, paying her 1 coin. She will tell you about Delrith and that you are destined to kill him, then direct you to Sir Prysin for the Silverlight Sword. Ask her, "What is the magical incantation?"

Find Sir Prysin in the Varrock Castle (north of the Gypsy), usually in the west wing wearing a helmet. Speak to him about the keys.

Go north inside the castle from Sir Prysin and find a ladder leading up. Ascend the ladder and locate Captain Rovin. Talk to him about the keys, tell him your story, and ask for the key; he will give you one.

Obtain a bucket and fill it with water. Return to Varrock Castle and use the water-filled bucket on the drain on the east side of the building to send a key into the sewer.

Go to the east side of the castle and enter the sewer through the manhole. Proceed past a level 8 rat (or search the area near the ladder if none is present) until you see a red dot on the minimap (the game's map). Avoid areas with scorpions or zombies, as you have gone too far. Retrieve the key.

While in the sewer, turn back towards the ladder and kill rats to collect at least 25 bones for the final key. You can bank if needed, then head towards the Wizard's Tower, located south of Draynor Village or west from Lumbridge then south from Draynor.

Enter the Wizard's Tower and go up the first ladder. Speak to Traiborn the Wizard. He will ask for 25 bones for a magic spell to unlock a key. Give him the 25 bones one at a time; after the 25th bone, he will cast a spell and give you a key. You should now possess three keys: one from Captain Rovin, one from the Varrock sewer, and one from Traiborn.

Return to Varrock Castle and speak to Sir Prysin again. Give him the three keys, and he will give you the Silverlight Sword.

Equip the Silverlight Sword and some armor, then travel southeast of Varrock to the Delrith, near the Stone Hedge. Attack the level 30 Delrith. After hitting him a few times, you will be prompted to recall the incantation. Click the very bottom option in the spell list that appears in the top left corner of your HUD (Heads-Up Display): "Carlem Aber Camerinthum Purchai Gabindo." After Delrith regenerates health, click the same incantation option again. Delrith will then die, completing the quest.