The Puppet Masters is a 1951 science fiction novel by American writer Robert A. Heinlein, in which American secret agents battle parasitic invaders from outer space. It was originally serialized in Galaxy Science Fiction (September, October, and November 1951). The novel evokes a sense of paranoia and Heinlein repeatedly makes explicit the analogy between the mind-controlling parasites and the Communist Russians, echoing the prevailing Second Red Scare in the United States. George Stubbins noted "Two particularly disturbing scenes in The Puppet Masters—the one in which members of the President's privately created Security Service hold at gunpoint the entire membership of both Houses of Congress and proceed to search out the traitors among therm, and that in which armed vigilantes roam the streets in search of traitors and shoot to death with impunity anyone they suspect of being such. Both scenes make sense in the context of the book's Science Fictional setting, and both are highly scary if applied to real American life." The book takes up the then common theme of sightings of flying saucers, the plot assuming that the "saucers" seen in the 1950s were part of a preliminary reconnaissance of Earth, carried out by the extraterrestrials in preparation for a full-fledged invasion sixty years later. Background The novel starts in 2007. Following a nuclear war between the Soviet Union and the Western Bloc, which left both sides battered but unbroken, both sides return to a state of Cold War. Washington, DC and other US cities devastated in nuclear strikes had been completely rebuilt. The Soviet Union and China remain a single bloc dominated by Moscow, and the sharp Sino-Soviet split of the late 1950s never happened. Social customs have changed somewhat, in a way typical for Heinlein's fiction (i.e. having become more liberal, such as marriage contracts being possible with fixed terms, etc.) and ray guns and personal flying cars are commonplace. "Slug throwing guns" remain in possession of some private citizens, but are considered obsolete by professionals. Space stations exist and colonies have been established on the planet Venus (depicted, as common in science fiction of the time, as a tropical planet habitable by humans). Space technology is far more advanced than in the actual first decade of the 21st century. For example, in the last scene, a space warship is sent on a twelve-year trip to Titan, with not only life-support for a large crew, but