This achievement is missable and can be done entirely in Part 4. You need to examine all 5 copies of "At The End Of The Plank", a purple-covered book scattered in the game. They are located in:
- Locke Smith's shop on the right
- The governor's mansion in the bookcase
- The fish shop once it opens
- The ice castle on BRRR Muda Island (before you become the queen)
- Herman Toothrot's cave on Terror Island (before you steal the key)
Bookworm Achievement: