| less depending on your prayer level

Talk to King Arthur in Camelot Castle. He will task you with retrieving the Holy Grail and direct you to Merlin for more details.

Go upstairs to the lab and talk to Merlin. He will tell you about Sir Galahad, who lives west of McGrubor's Woods.

Go to Brother Galahad's house, located directly west of McGrubor's Woods. He will explain that he once found the grail but left it where it belonged.

Travel to Port Sarim and take a boat to Entrana Island. Ensure you have no weapons or armor equipped.

On Entrana, go to the church and speak with the High Priest. Express your interest in finding the Holy Grail. The Crone will interrupt and tell you about the Fisher King's pain, instructing you to blow a whistle where all six heads point. Ask her about the whistle and how to obtain it.

Return to Brother Galahad and ask him for an item. He will give you a Holy Table Napkin.

Go to Draynor Manor (north of Draynor Village). On the top floor, enter the easternmost room. You must have the napkin in your inventory to see the magic whistle. Pick up two magic whistles, as you will need a second one later.

Prepare to fight the level 146 Black Knight Titan. It is recommended to have a prayer level of 37 to paralyze it. Bring your Excalibur from the Merlin's Crystal quest. If you don't have it, speak to the Lady of the Lake to obtain another.

Travel to Brimhaven. Head west until you reach the poison scorpions. Step onto a small platform and blow the whistle to be teleported.

Head west and talk to the Black Knight Titan to initiate the fight. This is considered the hardest part of the quest.

After defeating the Titan, go around the fence and towards the small peninsula. Talk to the fisherman and ask how to enter the adjacent castle. He will instruct you to pick up and ring one of the bells.

Go to the side of the castle, where a bell will have appeared. Pick it up and ring it to be teleported inside.

Speak with the Fisher King inside the castle. He will tell you about his missing son and his hope for his barren land to be restored.

Use the whistle to exit the castle and return to Camelot.

In Camelot, talk to King Arthur and ask about the Fisher King's son. He will give you a magical feather to guide you.

Go to Goblin Village and enter the westernmost hut. Right-click on the sacks and prod them. The Fisher King's son will appear. Tell him his father wishes to speak with him and give him the whistle.

Return to the Fisher King's Castle. Speak to the Fisher King, who will express his happiness at his son's return.

Go upstairs and then up the ladder to retrieve the Holy Grail.

Return to Camelot and speak with King Arthur to receive your reward.