I "borrowed" this from a WT.........
Go forward to the end of the room. Open the roll top desk. Pick up the chessboard paper. Use crowbar of the inside panel on the left side of the desk. A parchment rolls out. Look close on the parchment. Get the translated parchment with 2 square-shaped holes. Click it over the desk parchment. Then click on different shapes to move the translated parchment.
Note the geometric shapes that, when selected/clicked on, shows a roman numeral number on the other squared-shaped hole. The opposite square-shaped hole will show only a part of the selected shape. There will be 2 shapes with corresponding numbers on the
desk parchment seen. Turn the translated parchment over and do it again. There will be 2 more shapes with corresponding numbers seen. They are I - 3 dimensional cube, II - Sphere made up of triangles, III - Pyramidoid with 4 sided base made up of triangles and IV - starburst made up of triangles.
Turn around, move forward, turn right and look close at the engraved panel between the bookcases. Click on it and a wooden frame is revealed showing the geometric shapes shown on the desk parchment. Click on the geometric shapes in consecutive order
shown by the roman numeral number associated with the shapes."
Hope it helps!