The Flash must outwit a clever crook who uses the fear of the unknown as a weapon to bring Keystone City to its knees!; Black Canary and Larry track down some crooks who have stolen a professor's new forumla: Element X-99.; As a favor to the man who once saved his life, Carter Hall appears aboard a man's yacht as the Hawkman, little knowing his enemy the Ghost is also along for the ride.