Book downstairs has the key to the first door, then just keep going back through 2 or 3 of the portals (right after you come out)....last one is the room with the tub and fish on the wall...play with the fish and he will take a minute and then leave removing the barrier (not sure if playing with the fish did it :P). Then you are out and to the next little area where you can go outside to the pyre.
