Step 1. First, waddle to the book room which can be accessed from the coffee shop.
Step 2. Now click on the book on the book shelf to open the bookshelf.
Step 3. Click on 'The journal of captain Rockhopper' located on the lower right of the book shelf.
Step 4. Go to the very last page of the book. You will now see a key. Click on it to pick it up.
Step 5. After clicking on it click 'Yes' to add Rockhopper's key to your penguin's inventory.
Congratulations, you successfully found and obtained Rockhopper's key. Now when Rockhopper arrives on the club penguin island you can access the captains quarters on the Migrator. We hoped we helped.
