Required:

Skills: Level 40 Farming, Level 50 Fishing, Level 47 Prayer, Level 42 Crafting, Level 42 Slayer

Items: None

Quests: Zogre Flesh Eaters

Suggested:

Items: Ectophial, seed dibber, rake, watering can (if you don't want to fight some diseased spiders). Also, slayer gloves or Relicym's balm help you fight the disease.

Monsters: Fever Spider (Level 49), Evil Spirit (Level 150)

Teleport to Port Phasmatys with your ectophial, or walk by going East from Canifis. Don't enter the port but go to the Northeastern tip of it to find Pirate Pete on a small dock.

Talk to him. Offer to help by killing the demon. Also, reject the money and tell him that you will do it for free. You get knocked out and transferred to an island with a little cutscene.

You talk to Captain Braindeath. He briefs you about your mission, and wants you to grow some Blindweed for him. You get the seeds. Go downstairs to the cellar of the house and and search the cupboard in the Southeastern-most corner to find a rake, seed dibber and watering can. You can skip this step if you already have these items with you. Go back up upstairs and walk South to the farming grounds. Right-click on the swabs and choose intimidate. If they attack you, just run behind any obstacle and intimidate them from a distance. Now they will hopefully leave you alone. Plant the blindweed and wait for it to grow. Once it's ready, pick it and go talk to Captain Braindeath. Go upstairs to the Northwestern part of the house. Use your blindweed with the hopper and go back to Captain Braindeath. Talk to him.

Captain Braindeath tells you to get stagnant water from the volcano to the North. He gives you a bucket (or you can pick up the bucket from the ground.) Go downstairs to the Southern part of the house. Then go around the fence from the North side and run West until you come to a bridge. Try to open the gate, and you will make a great diversion to get past the guard. Run North and up the mountain to the stagnant water. Use your bucket on it. Go back to the brewery and use your bucket of stagnant water on the hopper where you put the blindweed. Then talk to Captain Braindeath again. He will give you a fishbowl and a net.

Go back downstairs and go to the Southeastern tip of the island. Fish at the fishing spot until you catch five Karamthulhu and sluglings. It doesn't matter which fish you get, just make sure you get five. Fill the pressure barrel on the top floor of the brewery with your catches until it's full. Then pull the pressure lever and check back with Captain Braindeath. He will tell you that the brewery is possessed, and will give you a wrench.

Talk to Davey in the Western part of the house. He will bless your wrench if you have level 47 prayer. Note that you have to have the charge at 47, maximum level doesn't count here! After getting the wrench blessed, go back to the main house and use your blessed wrench on the Brewing Control there. Kill the level 150 Evil Spirit and talk to the Captain once more. Now he needs the last ingredient for his... um...rum, and he asks you to kill a diseased Fever Spider. Go to the cellar and kill a Fever Spider. If you don't want to get diseased, you need to wear protective slayer gloves, which you can get from any slayer master. If you DO get diseased, you can heal yourself with Relicym's Balm. Refer to the Herblore Guide for more information on making Relicym's Balm. Pick up the dead spider's body and go back to the hopper.

After you have put the Fever Spider into the hopper, go talk to Captain Braindeath once more. You will see the rum come down. Now, use your empty bucket on the Output Tap (located on the Southern part of the brass brewing machine) to get the rum. Go downstairs and South. Look for Captain Donnie in the zombie crowd and talk to him. He will drink the rum and tell the name of his boss. Go back to Captain Braindeath. After a short dialogue he will reward you.