As kirito traveled through the depths of the underground dungeon, he had found what appeared to be a room full of lava with the heat radiating off the sides, making the room a furnace, to match the name of the dungeon. There were individual rocks that were laid across the pool, to the other side and he took a step back to gain momentum. He then used his spectral hand to steady himself, then started to run quickly and jumped from rock to rock, eventually making it to the otherside. There was a door that was locked from this side, however he was able to have his spectral hand go through and open it from the other side and was able to make it through the trial in one piece. The room he had entered was a huge cavernous structure that appeared to have lava filling the walls. He was ready for what lies ahead.