The Hollows series (also called the Rachel Morgan series) is a series of 15 urban fantasy novels by Kim Harrison, published by HarperCollins Publishers, in an alternate history universe and set primarily in the city of Cincinnati and its suburbs. The alternate history is built upon two premises: the recent open existence of magical and supernatural species, primarily witches, vampires, and werewolves, with the human population; and the historical investment of Cold War military spending in genetic engineering as opposed to the Space Race, which resulted in the accidental release of a genetically modified tomato in the 1960s that killed a significant portion of the human population. The series is set approximately 40 years after this plague, referred to as ”The Turn“ within the series.
The series is told in the first-person point of view of Rachel Morgan, a bounty hunter witch who works with local law enforcement agencies and faces threats both mundane and supernatural in origin. The series also focuses on Rachel’s relationships with her partners, a living vampire and a pixy, as well as her personal relationships with males of different species.