Before the start of WWII, the infamous Black Dragon Society of Japan, with the help of the Nazis, employ a noted plastic surgeon to transform six Japanese operatives into look-alikes for six highly placed American businessmen. The plan is to kill the Americans, replace them with the Japanese, and undermine the American war effort from the inside. The plastic surgeon who makes it all possible, played by Bela Lugosi, is betrayed by the Japanese government and imprisoned so he can’t tell anyone about the evil plan. He escapes and travels to America, where he kills five of the Japanese impostors, one by one. An American detective must find the killer’s identity before he kills the last man.