The Great Brain Robbery Quest Guide
OSRS The Great Brain Robbery walkthrough, requirements and rewards
Updated September 2026
The Great Brain Robbery is an Experienced medium quest that rewards 6,000 Prayer experience and 3,000 Crafting experience. It requires 16 Crafting (not boostable), 30 Construction (not boostable), 50 Prayer (not boostable).
On this page
6 sections
Overview
| Difficulty | Experienced |
| Length | Medium |
| Quest points | 2 |
| Series | Pirate |
| Start point | Talk to Brother Tranquility in Mos Le'Harmless. |
Requirements
Skill Requirements
| Skill | Level |
|---|---|
| Crafting | 16 (not boostable) |
| Construction | 30 (not boostable) |
| Prayer | 50 (not boostable) |
Quest Requirements
- Creature of Fenkenstrain
- Cabin Fever
- Recipe for Disaster (Freeing Pirate Pete)
Other Requirements
- Access to a player-owned house workshop and crafting table or the Grand Exchange
- Be able to kill a level 190 monster that can disable Prayers (can be safespotted without taking damage).
Items Needed
- Equipment to breathe underwater:
- A fishbowl helmet and a diving apparatus (reobtainable from Murphy in Port Khazard if you've lost them)
- OR a Medallion of the Deep (counts as both helmet and apparatus)
- 10 wooden cats – partial completion of The Great Brain Robbery is required to make these yourself, however they are tradeable and available at the Grand Exchange
- 4 oak planks, a hammer, and a saw (if you are building your own crafting table and do not already have one; build in the Clockmaking space of the Workshop)
- 10 planks (if making your own wooden cats)
- 10 pieces of fur: fur, bear fur, or grey wolf fur (if making your own wooden cats) (wolf fur can be obtained during quest by killing Canifis townsfolk. Baraek sells them for 20 gold each. Furs from Hunter monsters will not work)
- A hammer (Note: Imcando hammer does not work)
- About 100 nails (38 are needed, but some—especially bronze or iron—may bend)
- 8 normal planks (18 if making the wooden cats instead of buying them from the Grand Exchange)
- Holy symbol
- Ring of Charos (if lost, can be re-obtained during quest by pickpocketing Fenkenstrain)
Recommended
- 60 Combat
- Means of teleportation to Port Phasmatys (through the Ectophial)
- Charged combat bracelet to teleport to the Monastery (or a charged amulet of glory to teleport to nearby Edgeville)
- Runes to cast Fenkenstrain's Castle Teleport twice (or its magic tablet equivalent)
- If making the wooden cats, runes to teleport to your (or another player's) house, or its magic tablet equivalent, are highly recommended.
- Three watermelon seeds, rake, seed dibber, and ultracompost to complete a step in the Hard Morytania Diary (requires 47 Farming).
- Weapon and armour (ranging or maging gear is highly recommended as safespotting is available)
- Food and prayer potions are highly recommended
- Plank sack can be used for making the wooden cats and building the crate, saving inventory space.
Walkthrough
Video walkthrough by Slayermusiq1.
- Scouting. Talk to Brother Tranquility on Mos Le'Harmless near the dock. (Finish the dialogue, or you will be teleported back to Mos Le' Harmless) When doing the Hard Morytania Diary task, plant watermelon seeds now to be able to harvest them at the end of the quest. Beware of aggressive Level 57 zombie pirates throughout the island.
- The prayer book. Read the book. Equip a Holy Symbol and return to Mos Le' Harmless. Talk to Brother Tranquility to return to Harmony Island.
- The doctor. Talk to Dr Fenkenstrain (jail on the top floor of his castle north-east of Canifis). To get to the jail take the stairs to the east or west. Walk through the metal gate.
- Making the transplants. Return to Harmony Island and enter the windmill basement. Talk to Dr Fenkenstrain. Equip your item(s) to breathe underwater before leaving the windmill and go north to the shipwreck.
- The big battle. Return to the Harmony island monastery and Confront Mi-Gor to start the fight against Barrelchest. You must wear your equipment to breathe underwater. Each attack will disable your prayer and remove a few prayer points.
Rewards
- 6,000 Prayer experience
- 3,000 Crafting experience
- 2,000 Construction experience
- Blessed lamp (5,000 experience in a chosen skill above level 30 and can be placed in your bank)
- Barrelchest anchor (To repair your barrelchest anchor, return to Mos Le'Harmless and make sure you have a book o' Piracy in your inventory; then, go to the docks south of the bank and talk to "Smith." He can fix your anchor for 230,000 coins.)
- Prayer book
- Ability to cast Harmony Island Teleport on the Arceuus spellbook
- Ability to fight the Barrelchest within the Nightmare Zone.
Related Quests
Related Tools
The Great Brain Robbery FAQ
01What are the requirements for The Great Brain Robbery?
16 Crafting (not boostable), 30 Construction (not boostable), 50 Prayer (not boostable). Completion of Creature of Fenkenstrain, Cabin Fever, Recipe for Disaster (Freeing Pirate Pete). Access to a player-owned house workshop and crafting table or the Grand Exchange; Be able to kill a level 190 monster that can disable Prayers (can be safespotted without taking damage).
02What items do I need for The Great Brain Robbery?
Equipment to breathe underwater:, A fishbowl helmet and a diving apparatus (reobtainable from Murphy in Port Khazard if you've lost them), OR a Medallion of the Deep (counts as both helmet and apparatus), 10 wooden cats – partial completion of The Great Brain Robbery is required to make these yourself, however they are tradeable and available at the Grand Exchange, 4 oak planks, a hammer, and a saw (if you are building your own crafting table and do not already have one; build in the Clockmaking space of the Workshop), 10 planks (if making your own wooden cats), 10 pieces of fur: fur, bear fur, or grey wolf fur (if making your own wooden cats) (wolf fur can be obtained during quest by killing Canifis townsfolk. Baraek sells them for 20 gold each. Furs from Hunter monsters will not work), A hammer (Note: Imcando hammer does not work), About 100 nails (38 are needed, but some—especially bronze or iron—may bend), 8 normal planks (18 if making the wooden cats instead of buying them from the Grand Exchange), Holy symbol, Ring of Charos (if lost, can be re-obtained during quest by pickpocketing Fenkenstrain).
03What are the rewards for The Great Brain Robbery?
6,000 Prayer experience; 3,000 Crafting experience; 2,000 Construction experience; Blessed lamp (5,000 experience in a chosen skill above level 30 and can be placed in your bank); Barrelchest anchor (To repair your barrelchest anchor, return to Mos Le'Harmless and make sure you have a book o' Piracy in your inventory; then, go to the docks south of the bank and talk to "Smith." He can fix your anchor for 230,000 coins.); Prayer book; Ability to cast Harmony Island Teleport on the Arceuus spellbook; Ability to fight the Barrelchest within the Nightmare Zone.
04How long does The Great Brain Robbery take?
The Great Brain Robbery is rated Experienced difficulty and medium in length.
05How do I beat the Barrelchest in The Great Brain Robbery?
The level 190 Barrelchest can disable your prayers and hits hard, but it can be safespotted without taking damage; bring the diving apparatus or Medallion of the Deep for the underwater section.
06What does The Great Brain Robbery unlock?
It gives the Barrelchest anchor, a blessed lamp, the prayer book and the Harmony Island Teleport, and is required for the Hard Morytania Diary.
07What should ironmen know before The Great Brain Robbery?
You need 10 wooden cats (tradeable, or make them yourself with a crafting table) and underwater breathing gear; repairing the Barrelchest anchor afterwards costs 230,000 coins.
Next Quest
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Darren started playing the original RuneScape 2 back in the day and came back when Old School RuneScape launched. He's played on and off over the years and built OSRSToolkit to give players a single place to find reliable tools, calculators, and guides — all informed by real in-game experience.