"Halt!" cried Gandalf, who appeared suddenly, and stood alone, with arms uplifted, between the advancing dwarves and the ranks awaiting them. "Halt!" he called in a voice like thunder, and his staff blazed forth with a flash like the lightning. "Dread has come upon you all! Alas! it has come more swiftly than I guessed. The Goblins are upon you! Bolg of the North is coming. O Dain! whose father you slew in Moria. Behold! the bats are above his army like a sea of locusts. They ride upon wolves and Wargs are in their train!"
The Clouds Burst, The Hobbit