The Men from U.N.C.L.E., Napoleon Solo (Robert Vaughn), Ilya Kuryakin (David McCallum) and Alexander Waverly (Leo G. Carroll), travel to a fortress in the deserts of Iran, home of the megalomaniac Luther Sebastian (Bradford Dillman). Posing as the leader of a religious cult, Sebastian has developed a nuclear prism designed to focus "death rays" on defenseless aircraft.