The Fellowship of the Ring Book 2, Chapter 5
"The Company of the Ring stood silent beside the tomb of Balin. Frodo thought of Bilbo and his long friendship with the dwarf, and of Balin's visit to the Shire long ago. In that dusty chamber in the mountains it seemed a thousand years ago and on the other side of the world." Book 2, Chapter 5, pg. 381
They search around to find a hint of Balin's fate. There are weapons lying around and some bones. They find orc weapons. They also find a dusty book: a sort of journal of the settlement. It tells of the dwarves' ongoing struggle with orcs. The death of Balin is described. He died fighting orcs. The last page says that they are trapped and cannot get out. From the book, Gandalf discerns how to get to the main gate and exit the mines. There is a great noise and then the sound of orc drums. Gandalf peers into the tunnels and sees oncoming orcs and trolls. They shut and bar the western door. The door is broken down after repeated beating. They make a brief stand and fight bravely, but Gandalf yells for them to retreat and exit through the eastern door. Once they get out, he yells for them to keep going and let him hold the door alone. They pause, but he continues to yell. They rush on into the narrow tunnel. The sound of pursuit stops. They ask Gandalf what he did. He heard something enter the chamber and the walls within collapsed. He feared the sound. Frodo was hit with a spear and carried out of the chamber by Aragorn. He speaks and says that he is fine, relieving their fears. They continue into the tunnel and see a light forming ahead. It begins to get hot in the tunnel and Gandalf thinks that the lower levels of Moria are on fire. They come to the final bridge and his fears are realized. It is narrow and has no rail. It must be crossed in single file. Arrows fall around them as they begin to cross. The orcs are nearing them again. A creature appears ahead of them with a sword of fire. It is the Balrog, the evil creature that the dwarves released when they mined too deeply. They fly over the bridge and Gandalf turns to face the Balrog. He speaks to it and tells it that it cannot pass. He breaks his staff on the bridge and the bridge begins to crack. The creature slips and begins to fall into the burning depths, but it grabs Gandalf with one of its limbs. Gandalf's strength holds out for a moment and he urges his companions to flee as quickly as possible. The others were around a corner and could not see this, but Boromir and Aragorn watched Gandalf slip away. They turned and ran yelling for the others to move more quickly. They hasten down the corridors and make their way out the eastern gates. Once out, the drum beats fade away until there is silence. It is the middle of the day. The sun is shining. They collapse to the ground and weep.