A New York cop is challenged by a bizarre double murder in which two women, a prostitute and a prim teacher, are killed on the same night, decapitated, and their heads switched, in this two-part four-hour thriller based on William Bayer's bestseller, "Switch." The book's title also was to have been the film's except for the possible confusion arising when the old Robert Wagner-Eddie Albert series of that name was recalled. Filming was done entirely in and around New York City.