The CSI team investigates the murder of a man suffering from a congenital hypertrichosis, causing him to grow excessive body hair. Elements of the case suggest a connection with a belief in werewolves. The case leads to the victim's sister, who suffers from the same disease. Because of her condition, she'd been hiding from the world, but it turns out that she's hiding facts that are vital to solving the case.
In the city of Las Vegas, Nevada, its reputation for providing instant success for those willing to try their luck draws in the hopeful and the naive. This constant influx of visitors also provides ripe targets for criminals of all varieties, confident they will never be caught. Unfortunately for them, most are proven wrong by the Las Vegas Police Department's night shift Crime Scene Investigations unit led by ex-stripper and single parent Catherine Willows.
With almost obsessive dedication towards her quest for the facts, she and her elite team of investigators work various perplexing cases using scientific skills and equipment that are capable of finding valuable clues from the most seemingly unlikely sources.
Her team includes second-in-command Nick Stokes, who was Texas-born and -bred; Sara Sidle, who recently returned from a leave of absence; Greg Sanders, a former DNA Tech, and Morgan Brody, daughter of the under-sheriff and new transfer from Los Angeles, California. Assisting them are Jim Brass, an experienced LVPD Captain; Al Robbins and David Phillips, the Chief ME and his assistant; and David Hodges, a trace technician who hates field work.