Moreover the company found an old book, which they identified as the story of Balin's folk until they had reached Moria 30 years ago. The book ended with an assault of the Orcs, which had taken the mines after the great evil, which the Dwarfs called Durin's bane, had arrived at Moria. And now, like a bad horoscope, the party also heard the drums beat and the Orcs cry. They blocked the chamber of Balin's grave and escaped through another door but Gandalf remained at the door to close it by magic. Here a great power appeared and nearly destroyed the old wizard but he escaped and the whole chamber collapsed. The party now ran for the exit, and they nearly reached it.
But as they were almost out, the great power reappeared and the whole company was shocked. It was a Balrog. A monster, created by the evil Morgoth, God of Darkness, hundreds of centuries ago. He had slept under the mountains, until the Dwarfs disturbed him and now he was the master of the mines. In a final fight on the bridge before the exit, Gandalf and the Balrog fell down in an deep chasm and disappeared. The others, sad about their great loss, left the mines through the eastern gate and never got their later.