This guide is suitable for current RuneScape and Old School.
Talk to Grish, who can be found west of Gu'Tanoth, and south of Castle Wars.
Investigating the Cave
He will warn you to stay away in case you get infected with the "sickies" and upon you enquiring further, will ask you to find out why the Zogres have appeared. Speak to the Ogre guard and tell him Grish sent you, and he will knock down the barricade. Climb through it, go down the stairs and make your way to the north-western side of the cave by a broken lectern. After the cutscene, search the broken lectern to receive a torn page. Next, search the skeleton and a level 39 Zombie will materialise and attack you.
Upon defeating the Zombie you will get a ruined backpack. Open it to a find a Knife, a Dragon Inn tankard and some rotten food. Continue to search the tomb nearby, and then use a knife with it and push it open. If you fail to open it, you may lose a strength level temporarily. You will find a black prism inside the tomb. Head over to Yanille and enter the Dragon Head inn pub and show the tankard to the barman. He will recognise it as Brentle Vahn's tankard, however he hasn't seen him in a while. You will have a feeling that he has been murdered, and the barman will tell you that he last saw Brentle talking to a wizard.
Seeking the Wizards help
Make your way to the Wizards' Guild and ring the bell, and show Zavistic Rarve the torn page. He will tell you that a curse has been inflicted with the prism, and will inform you that a wizard named Sithik Ints was doing research in the area and is currently bedridden in the guest house to the north, so suggests speaking to him.
Go into the house to the north and climb upstairs and speak to Sithik Ints lying in the bed in the west room. Search his room to receive a book on necromancy, a book from H.A.M and a book on portraiture as well as some Papyrus and Charcoal. Read the portraiture book and then use the Papyrus on Sithik to draw his portrait. You many need to do several portraits with additional papyrus until you get the examine "A classic realistic interpretation" on the Sithik portrait. When you have the realistic portrait, take it to the barman in the Dragon Head inn and ask him to sign it. Return back to the Guild and show Zavistic all of your evidence. He will give you a strange potion and tell you to use it on Sithik.
Attempt to use the potion on Sithik however he will not accept it so use the potion on his cup of tea. Return back to Zavistic and he will tell you to go back and check on Sithik. You will see that the potion has transformed Sithik into a ogre, and will not reverse its effects until he speaks the truth. He will tell you how to make brutal arrows, and the two herbs Rouge's Purse and Snake Weed which can be found in Karamja. Make your way to Karamja and collect and clean the herbs, and then use them with a vial of water to create Relicym's balm.
The locations are shown below.
Note: Fight ahead, level 111.
Now create brutal arrows by using the nails on the flighted ogre arrows. It is recommended to have around 100. Return back to Grish and fill him in with the information you have gathered. In order to relocate the ceremonial grounds, he requires you to get him an artefact and will give you an Ogre gate key. He will also teach you how to make a Composite ogre bow (which requires Wolf bones, an Achey tree log and a Bowstring to make). When you have made the bow, climb through the barricade, down the stairs and then head west through the tunnel until you come to a gate. Use the Ogre gate key on the two gates. Search the stand and you will attacked by Slash Bash (level 111). He uses melee and ranged combat attacks, however his melee is stronger so it is advisable to use Protect from Melee.
When Slash Bash has been defeated, pick up the artefact he drops and return it to Grish.
Congratulations! Quest Complete!
Guide Made by: DaDa
Corrections submitted by: Marc J, Power of Five, Tainted Tbh