A tracer cloud is attached to a an object, by a wizard, or someone else using magic, to track the location of someone without having to directly follow them. Darken Rahl used a tracer cloud on Richard Cypher, until Zeddicus Zu'l Zorander cast a spell, so that the tracer cloud attracted other clouds. This meant that when Richard and Kahlan entered the Mud People's land the Mud People thought that Richard was a spirit who had brought the rain with him, as their spirits had told them one would.