Captain Britt was a Confederate captain during the American Civil War. While in the desert, he and his command troop discovered an interesting machine.
Amy Pond and Barnardo raided his camp and stole the machine, and Britt and his men were forced to follow. After catching the runaway train, which was separated, he managed to capture Amy and bring her back to camp. Before they returned there, he was astonished to find a flying disk in the sky, which completely destroyed the camp. Instead, they turned around and headed towards the runaway train's direction.
Upon arrival, he put a creature known as the Cei at gunpoint. It revealed an alien weapon from its person and pointed it back at him. The Eleventh Doctor managed to time an explosion, which knocked both of them flat. Britt was forced to go away. (AUDIO: The Runaway Train)