theme of the novel. By using alien settings to consider what it means to be different, Asaro looks at conflicts inherent in different cultures and peoples on our own world. Other works listed as similar to Catch the Lighting are Nekropolis by Maureen F. McHugh, Brothers in Arms by Lois McMaster Bujold, Master of Intrigue by Mary Ann Steele, Venus by Ben Bova and Heart of the Betrayed by Angela Verdenius. Raylicon and origins of the saga Catch the Lightning is the Skolian book that most features the world Raylicon, ancient home of the "lost children," those humans taken from Earth thousands of years ago and stranded on Raylicon. The mystery of why a starfaring species moved humans to a dying world and then disappeared, leaving nothing behind but the wreckage of starships, is a central question of the saga. The displaced humans eventually conquer space flight and raise the interstellar Ruby Empire. Built with only partially understood technology, it falls three centuries later, and it takes another four thousand years for the Raylicans to regain the stars. (The Radiant Seas, 1999) During that time, the colonies on other worlds are stranded, and those that survive lose their technology, becoming lost worlds. Raylicon is the culture that survives, and in modern times the mysterious ruins of the Ruby Empire exist side by side with the modern cities of the Skolian Imperialate. The chapters set on Raylicon, which come late in the book, offer the most detail in the saga about the culture and history of world that originated both the Skolians and their enemies, the Eubian Concord, aka the Trader Empire. Mathematical and physical themes Asaro, a theoretical physicist, frames the science fictional elements of the story with mathematical concepts. The alternate universe Althor slips into when his ship malfunctions is a fictional extrapolation of Riemann sheets and branch points from complex analysis. The concepts derive from an extension of special relativity into the complex plane, as described in a paper Asaro published in the American Journal of Physics. She also uses concepts of Hilbert spaces in sequences of Catch the Lighting, as detailed in the essay at the end of her book Spherical Harmonic. Asaro's Nebula Award winning novella "The Spacetime Pool" further uses the ideas of Riemann sheets and branch points to structure the story. Genre splitting As with several of Asaro's other works, Catch the Lightning has