This anthology presents a collection of speculative narratives centered on the evolution and transformation of human consciousness. Each story explores the psychological and physical ramifications of cognitive shifts, whether induced by technology, alien influence, or evolutionary leaps. The protagonists navigate worlds where the boundaries of the mind are challenged by external forces or internal mutations. The narrative framework utilizes a variety of perspectives, ranging from clinical observations to intimate character studies, to examine the fragility of human identity.

Discussion often centers on the diverse range of voices included in this collection, noting the distinct stylistic approaches of contributors like Jerry Sohl and R.A. Lafferty. Readers frequently highlight the uneven nature of the stories, which is typical of mid-1970s science fiction anthologies. The thematic focus on the expansion of the human mind provides a cohesive thread that links the disparate narratives together. Critics often point to the experimental nature of the prose as a defining characteristic of the era's speculative output. The anthology serves as a snapshot of how science fiction writers of the time conceptualized the future of human intelligence.