Warning: This article contains major spoilers for Octopath Traveler 2!
During your many adventures in Octopath Traveler 2, you may have come across ‘??? Island‘ in the East Sundering Sea. The game gives you very little information on the purpose of its island, with destroyed structures, a sealed door, and a single save point. While it may seem like there’s nothing of interest here, ??? Island actually holds a huge endgame secret.
What is on ??? Island in Octopath Traveler 2?
The ‘??? Island’ found in the East Sundering Sea in Octopath Traveler is part of unlocking a secret optional battle with a major Superboss in what is undoubtedly the most brutal fight in the series.
The Mysterious Superboss on ??? Island
The most challenging boss in Octopath Traveler 2 is the Superboos ‘Galdera‘, who awaits the player on ‘??? Island‘ after completing Al‘s questlines. This fight is somehow even more difficult than in the original Octopath Traveler, though thankfully, you don’t have to fight eight bosses beforehand.
How To Unlock the Fight Against Galdera
Step 1: The Traveler’s Bag
The first step is to complete the ‘The Traveler’s Bag‘ sidequest, available at the end of Chapter 1 regardless of the character chosen as the player character at the beginning of the game. Defeat the thief found at a campfire close to the starting location and return the bag to Al.
Step 2: Procuring Peculiar Tomes
You’ll also need to complete “Procuring Peculiar Tomes,” which can be obtained from the Library in Montwise and requires you to acquire three specific books.
Dispatches from Beastling Island can be stolen or bought from a merchant in Beastling Village.
Far Reaches of Hell is in a chest in the lone guarded house in Crackridge. Knock the guard out and nab the book.
The Curious Legend of the Great Wall is in Southern Stormhail Snows, held by the Archeologist near the mountain entrance.
Step 3: From the Far Reaches of Hell
After you’ve handed each tome in and completed both the Procuring Peculiar Tomes and The Traveler’s Bag quests, you can start From the Far Reaches of Hell.
Approach Al in the Library, who you’ll find struggling to translate your newly acquired novel. Seek out Georges Lazuli on the Nameless Isle found north of Toto’haha. Defeat the boss Gigantes and you’ll be able to acquire How to Decipher Unknown Languages from George.
Take the tome back to Al to complete this quest and unlock the sealed door on ??? Island.
Step 4: Travel to ??? Island
Travel to ‘???‘ in The Sundering Sea and you should notice that the large door is now open. Enter the door to find an injured Al and a long staircase. If you think you’re ready, ascend the stairs and receive the warning: “The sense of danger is overwhelming. Are you certain you wish to proceed?”
Select ‘Yes,’ divide your party, and begin the battle against Galdera — the true final boss of Octopath Traveler 2.