In the watery area outside the Library, pull the submerged lever and start swimming. Stay close to the right walls, and go down the square hole. A flare will definitely come in handy here. Once you're all the way down, make a right and swim forward. Skim the floor, swimming through the openings, angling to the right. You'll find the gold statuette in the far-right corner. Escape by yanking the switch opposite the statuette and going up through the tunnel. Welcome back to the fire pad room.