Instructions
Click on the odd-looking wall next to you after the princess you handed your weapons to transforms into Binary Bard. This will cause a door to appear with five rows of four squares each.
Begin by clicking the squares in the second row from the top in the correct order. Click the third square from the left, the rightmost square, the second square from the left and then the leftmost square.
Click the second and then the third square from the left in the third row from the top.
Click the squares in the fourth row from the top in the following order: the rightmost square, the third square from the left, the second square from the left and then the leftmost square. This completes the puzzle, and you can now open the door.