"Tomorrow the World!" by Geoff St. Reynard is a science fiction narrative likely written in the early 1950s. The book explores themes of identity, evolution, and the conflict between different races, particularly the Neanderthal descendants and modern humanity. The story unfolds in a contemporary setting that delves into the primal instincts and memories of a man who experiences an awakening of his ancient heritage after committing an impulsive act of violence. The protagonist, Bill Cuff, is an adventure writer who unwittingly awakens a primal aspect of himself following a violent confrontation with a museum guard, where he discovers he is more than just a man—he is a descendant of the Neanderthals. As the narrative progresses, Cuff grapples with his newfound identity and physical abilities, reflecting on his lineage and the blood-tinged history between humans and Neanderthals. He encounters others like himself, known as the Old Companions, who share his ancient memories and instincts and are planning to reclaim their place in the world. The story culminates in a declaration of war against humanity, as the Neanderthals prepare to rise and assert their dominance, blending elements of horror and science fiction to challenge the concept of what it means to be human. (This is an automatically generated summary.)