They had hardly gone any distance down the tunnel when a blow smote the side of the mountain like the crash of battering-rams made of forest oaks and swung by giants. The rock boomed, the wall cracked, and stones fell from the roof on their heads. What would have happened if the door had still been open I don't like to think. They fled further down the tunnel glad to be still alive, while behind them outside they heard the roar and rumble of Smaug's fury. He was breaking rocks to pieces, smashing wall and cliff with the lashings of his huge tail, till their little lofty camping ground, the scorched grass, the thrush's stone, the snail-covered walls, the narrow ledge, and all disappeared in a jumble of smithereens, and an avalanche of splintered stones fell over the cliff into the valley below.

Chapter 12