After an atomic blast in the desert of New Mexico produces a breed of giant radioactive ants, the genetically reengineered arthropods wreak havoc on the Southwest until they eventually descend on the helpless citizens of Los Angeles. In this surprisingly understated science-fiction classic, the pervasive nuclear anxiety becomes manifest in the mutated insects. While this was a common trope of many 1950s B-movies, Them! stands out as one of the few intelligent explorations of the potential physical consequences of atomic testing and, more important, the psychic impact on the culture at large of the uncertain effects of new technologies.