This guide is suitable for current RuneScape and Old School.
Talk to King Roald, who is in the Varrock Palace.
He will tell you that a priest called Drezel hasn't contacted him yet, and is worried for his welfare. He will ask you to go and check upon him.
Finding the temple
Head east out of Varrock, and then head through the gate near the Lumberyard,and then follow the road down until you come to a Temple. Knock on the doors.
You will be asked to identify yourself. Respond answering that you have been sent by King Roald to check up on Drezel. You will overhear two people whispering a conversation about who Drezel is, and then one will answer claiming to be him. He will tell you that you can help them by killing a dog in the Mausoleum nearby.
Head north and climb down the trapdoor and you will see the Temple Guardian. Kill it, and be aware that magic attacks will not work. Once you have defeated the Guardian, head back to the Temple and knock on the door.
Report back the deed that you have done and you will be answered with laughter, and told to go tell King Roald. Head back to Varrock and talk to him.
Reporting back to Roald
King Roald will be furious with you, as you realise that you have been tricked and have killed the guardian which guards the entrance to Morytania.
Before heading back to the temple, make sure you grab your Bucket, as you will need it for the next part of this quest.
Head back to the Temple only to find it wide open, and overrun with Zamorakian monks. Head to the third floor and you will find Drezel locked up. Talk to him through the bars and he will tell you Saradomin's presence is weakening in Misthalin due to the creatures in Morytania polluting the Salve river, and you must help him to purify it. He will also tell you that the coffin nearby holds a vampire that would be more than eager to kill Drezel if he goes near it.
Purifying the Water
Kill the Monks of Zamorak until you get a golden key. Head down to the Mausoleum and go through the gate that was previously guarded by the Temple Guardian.
You will enter a room full of statues. Do not take from any, or else you will be damaged. Search the statues until you find one with a iron key, and then use the golden key on it to swap it. Also, while you are here fill your bucket up with water from the well.
Now head back to Drezel and use the iron key on his jail to free him. Give him the bucket of water that you just collected and he will bless it. Use the blessed water on the coffin and then talk to Drezel, and arrange to meet at the Mausoleum.
Head north-east past the statues and talk to Drezel. He will tell you that the River Salve is badly polluted and that a temporary barrier has been constructed to prevent evil forces crossing, but he can't keep it up for much longer. You will mention to him that you know of a rock that can absorb magical power called the Rune Essence and he will agree with you that it should work, and will ask for 50. (Note that 50 Pure Essence will also work).
You will have to make several trips to do so, so run to the bank and collect the essence and take it to Drezel and repeat until you have given him all 50. If you have access to the Giant pouch, you may only need to make one trip.
N.B. Only unnoted essence can be used.
Congratulations! Quest Complete!
Guide Made by: Chas433
Corrections submitted by: Doctor Shemp, DaDa, Jei, Rebecca, Majinvegito3, Power of Five, Strey