A Secret Legend achievement in TUNIC

Available in the Cathedral area, and requires you to have unlocked the dash ability through natural progression of the story. You will also need to be alive (attained the 6 golden upgrades at the Hero Graves), and you'll need to be able to switch between day and night at the Old House.

Start at Night Time, and head to the Swamp, Old Burial Grounds, and up to the Cathedral. Once there, take the closest door on your left to enter the room with the ladder shortcut. Interact with the wall behind the ladder to reveal a secret path. Inside, reveal another secret path to find a tunnel system and a secret room. At the back of the secret room is a line puzzle door that you can open, the answer is:
LEFT, UP, LEFT, UP, RIGHT, UP, LEFT, UP, RIGHT, DOWN, RIGHT, RIGHT, UP, RIGHT, DOWN, LEFT, DOWN, RIGHT, DOWN, LEFT, DOWN, LEFT

Once you open that door, head back to the Old House and sleep to make it day time. Head back towards the Cathedral, and just before entering it, head down the hidden ladder next to the door. You'll end up on the balcony that leads to the secret door we unlocked previously and you'll be able to access the chest now to unlock it.

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