HANG SHADOW HORSE The Portuguese slavers called him Sam because they couldn't pronounce his real name. They tore him away from his homeland and put him to work picking cotton in the Tennessee Valley. But the big, fleet-footed Zulu was nobody's slave, and to prove it he escaped and headed west. Throwing in with a medicine show conman named Doc Jonah, Sam started entering county footraces to earn enough money to go back to Africa. But then his trail...