Blue Tower Invisible Ink Memory Puzzle

At map coordinates 3740, 2140, northwest of the crane puzzle and southeast of the Blue Tower, is a blue building inside a large blue circle on the map. The boards on the outside of the building change every time the puzzle is activated, so you cannot just memorize a fixed set of five symbols. Inside the building are nine puzzle pieces whose symbols are written in invisible ink and only appear when viewed through the provided lens. Both players need to be in the room because the lens angle cannot be changed - one player holds up each piece while the other reads it. The door locks behind you, so memorize what each piece is before carrying them outside. A common trick is to sort the pieces next to matching statues and markers in the outdoor area - the loop statue, the red line, the rock, the triple-snowman statue, the lantern, the central triangle, and the star - then activate the puzzle and place the pieces in seconds.