Colin Whister, a man haunted by the disappearance of his sister Susan decades prior, seeks to reconcile his fragmented memories with the ancient, mythic forces that once defined his childhood. As an adult astrophysicist, Colin navigates a reality where the boundaries between scientific observation and primordial legend blur, forcing him to confront the psychological weight of his past. The narrative operates through a non-linear structure, oscillating between Colin’s present-day isolation and the primal, visceral experiences of a prehistoric ancestor. This duality serves to examine the persistence of trauma and the cyclical nature of human existence across vast stretches of time.

This work is widely regarded as a dense, challenging conclusion to a narrative arc that spans over half a century. Critics often highlight the stark contrast between the author's early, more accessible adventure writing and the complex, cerebral nature of this final installment. The text demands significant patience from the reader, as it eschews traditional plot resolution in favor of a meditative exploration of consciousness and myth. It is frequently analyzed as a profound meditation on the nature of time and the enduring impact of childhood experiences on the adult psyche.