Darla Harriet and Ian Shag for the British Secret Service are assigned by S to go undercover to do an espionage mission against the Soviets and get a microfilm with locations of the CIA and MI-6 and the Soviets possess such a microfilm, including another mission about an atomic bomb more powerful than THE MANHATTAN PROJECT in which is called OPERATION LOS ANGELES in which Mister Doctor No is the mad scientist who was to turn Los Angeles to dust and smoke. Does Darla and Ian get the microfilm from Japan and the Soviets? Read and see.