"Siegel, as ever rough-edged and machismo, is clearly taken with this smart screenplay's many levels, and deliberately lets this film run from terror to melodrama to comedy. As screenwriters were being blacklisted, he went for the jugular of American paranoia. As Kevin McCarthy and Dana Wynter, both hitting a shrill exaggeration in performance, dash about avoiding assimilation while no one listens, Siegel's isn't a work of paranoia; it's a sarcastic attack upon it." - Ian Nathan, Empire Magazine