There was a scream of tortured air over the Mojave Spaceport as a two-man starship dropped on its hot jets toward the wide cementalloy landing field. It slowed and settled gently to the ground. Before the faint wisps of smoke had time to dissipate, the airlock door opened, and a big, broad-shouldered man got out. He dropped lithely to the ground and started off across the field at a quick trot. He nearly bowled over a field attendant who had been coming toward him. "Hey!" the surprised attendant