The history of the planet Shikasta is chronicled through the reports of Canopean emissaries observing the catastrophic decline of humanity. The narrative follows the efforts of Johor, an agent from the advanced galactic empire of Canopus, as he attempts to guide the inhabitants of Shikasta through cycles of war, environmental collapse, and spiritual decay. The story unfolds through a complex, non-linear framework of official archives, personal journals, and historical documents that span millennia. These records detail the interference of rival galactic powers and the struggle to maintain a connection to the cosmic order amidst the chaos of human development.

Shikasta is widely recognized as a challenging and ambitious work that marks a significant shift in Doris Lessing's literary career toward speculative fiction. Critics often highlight the book's dense, intellectual structure and its departure from traditional narrative conventions in favor of a cosmic, historical perspective. The work is frequently discussed for its bleak yet profound examination of human history and the potential for spiritual or societal evolution. Readers often find the archival format both demanding and rewarding, as it forces a re-evaluation of human progress through an extraterrestrial lens. The novel remains a cornerstone of the Canopus in Argos cycle, celebrated for its intellectual rigor and visionary scope.