Suk School

In Frank Herbert's Dune Universe, the Suk School produces the universe's most competent, trusted doctors. Those who have received Suk training wear their hair in a special metal ring and, at least theoretically, are incapable of inflicting harm. This was proven false when Baron Vladimir Harkonnen tortured the wife of Dr. Wellington Yueh until he agreed to betray House Atreides; even so, Yueh allowed Paul and Jessica Atreides to escape and gave Duke Leto Atreides the means to kill the Baron (though the Duke failed to complete this task).