Following a free-spending night at an exclusive Las Vegas nightclub, the chairman of the Grey Rock Paiute Tribe is found brutally murdered in his home, a cryptic message scrawled on a wall in his own blood. Soon, crime scene investigators Ray Langston and Nick Stokes have their hands full with a growing mystery – already surrounded by controversy, the victim appears to have met his end from a crime of revenge, but the chairman's inner circle isn't talking about who or why… quickly leading to an escalation of violent retribution… At the same time, Catherine Willows and Greg Sanders investigate the mysterious shooting of a homeless man on the palatial estate of Helena Cameron – the widow of one of Sin City 's first casino tycoons. At first, it seems like an open-and-shut case of trespassing and self-defense… but the CSIs soon uncover layer upon layer of heartbreak and tragedy in connection to a family keeping secrets as old as Las Vegas itself…

A teenager is found dead in his motel room, the cause of death: millipede poison…Now crime scene investigator Gil Grissom must aid CSI's Nick Stokes and Riley Adams against a serial killer whose knowledge of entomology rivals his own – a brutal murderer who is not only using insects as the tools of destruction, but actually modeling the attacks after their behavior… In the meantime, CSIs Catherine Willows and Greg Sanders must investigate a bizarre death, where the victim had gotten mixed up with two very different groups of people – one involved in using and dealing crystal meth, the other an avant-garde group of artists – a collision of subcultures where everyone is a suspect and nothing is as it seems…