Go down into room 50970hpg.html (in the cellar)*. Move your mouse to the copyright notice at the very bottom of the window. Then hold down the left mouse button while you move the mouse up several inches. (Notice anything new appear on the screen? Like ... maybe a hidden message with the number 67576 in it?)

^*WARNING: You must get to this room legitimately! Do not try to "cheat" by simply "skipping ahead" to this part of the game! (If you do, you will miss important information that is needed later on!)