If you stand in front of the gold room in the hotel, there are 5 entrances. There is a number in front of every entrance. Knife every single number. Now run through door 1 then 5 and then 3. You are now in the backrooms. Interact with the fish and everything goes dark. Now there are 4 different phrases painted on the wall. you must activate these sentences in the correct order. After you have done that, go back to the middle, there you will find element 153.