** The Two Towers - Riders of Rohan

With astonishing speed and skill they checked their steeds, wheeled, and came charging round. Soon the three companions found themselves in a ring of horsemen moving in a running circle, up the hill-slope behind them and down, round and round them, and drawing ever inwards. Aragorn stood silent, and the other two sat without moving, wondering what way things would turn.

TTT, "The Riders of Rohan"