Rum Deal

Setting out
Talk to Pirate Pete at the dock north of the Ectofuntus. Agree to help him, and refuse the money he offers you. He will knock you out and take you to Braindeath Island.

Upon waking, you will find yourself in a small room. Talk to Captain Braindeath and he will tell you that he needs to make some "rum" in order to get Captain Donnie drunk. You will have to gather the ingredients to make the rum. The Captain will give you some seeds in order to grow the first ingredient.

Blindweed
If you brought a rake and a seed dibber you can skip this: ''The first ingredient is Blindweed. Go down the ladder in the northwest corner of the building and then head southeast to find a cupboard. Take everything from the cupboard (this is equipment for you to farm your seed) and return to the main floor. ''

Leave the building by the southernmost stairway. Walk south until you find some farming patches. The majority of them will be unusable; the southeastern one will still be available, however. Rake away the weeds and plant your seed. Wait for the blindweed to grow (about five minutes) and pick it. During this time you may be attacked by Zombie Swabs; find a convenient safe spot, such as the other side of the fence, and choose the right-click option "intimidate" to stop them from attacking you. You only have to scare each swab once. Return to Captain Braindeath and he will tell you to put the blindweed in the hopper. Use the southeastern ladder to go up one floor and use the blindweed with the hopper, in the northwestern corner. Return to Captain Braindeath to find the next ingredient.

Stagnant Water
To get stagnant water you will have to travel to a nearby volcano and fill a bucket which the Captain has given you. Leave the house via the south stairway again and travel northwest (make sure you're on the outside of the fence first) to find someone guarding a small gate. Open the gate and walk through - you will automatically make a diversion for the guard. Travel up the volcano and collect some stagnant water. Return to the house, put the water in the hopper and talk to Captain Braindeath.

Sluglings
The Captain will give you a fishbowl tangled in a big net and tell you to fish five "sluglings". Don't untangle the bowl and net! If you do, use one on the other to "retangle" them. Head to the farming patch you used earlier; the fishing spots are close by. Fish five sluglings; there is a chance you will get fish other than the sluglings, but it doesn't matter which fish you get. Return to the house but instead of putting the sluglings in the hopper you will have to "pressurise" them; put them in the pressure barrel and pull the lever. Then return to Captain Braindeath.

Evil Spirits
Note: If you wish to have multiple holy wrenches, you can use drop trick here to get them from Captain Braindeath and then go bless them.

Captain Braindeath will tell you that the controls for the brewery have become possessed. He will give you a wrench in order to beat the controls with it. Head to the west of the house and get your wrench blessed by Davey - he will only bless the wrench if you have 47 or more prayer points, not just level 47 in prayer. Now beat the controls with them and a level 150 Evil Spirit (pun intended) will appear, you can easily safe-spot with ranged/magic, or use a halberd behind the pylons to kill it.

Fever Spider
Captain Braindeath will tell you that the final ingredient is the carcass of a Fever spider. Go down the ladder near Captain Braindeath and kill a Fever spider - be warned that if you do not wear slayer gloves, you may become diseased, but if you are using magic or ranging the spiders, you can hide behind the ladder/boxes and attack one, you will not become diseased if you do this. Collect its carcass, use it with the hopper and talk to Captain Braindeath.

Captain Donnie
Now that the "rum" is complete, collect some from the "output tap" at the south end of the machinery. Head outside, to the farming patches. Find Captain Donnie and give him the "rum". After some dialogue he will tell you the name of his boss. Return to Captain Braindeath to claim your reward.

Rewards

 * 2 Quest points
 * 7,000  Fishing experience
 * 7,000  Prayer experience
 * 7,000  Farming experience
 * Holy wrench - if it is in your inventory whilst drinking prayer potions or super restore potions, you will restore more prayer points depending on your prayer level.