Focuses on the sometimes complex and always amusing dynamics of a team of special agents forced to work together in high-stress situations. From murder and espionage to terrorism and stolen submarines, these special agents travel the globe to investigate all crimes with Navy or Marine Corps ties.

Amidst the neon lights and long shadows, dark threats continue to lurk in Sin City. Maxine Roby leads her brilliant team of Crime Scene Investigators as they use science to solve baffling cases. Catherine Willows returns to help the CSIs face off with a dealer of death who is planning to beat the odds in Las Vegas. This combined force will deploy the latest forensic techniques in order to preserve and serve justice in Sin City.

The CSI team is on the case 24/7, scouring the scene, collecting irrefutable evidence, and finding the missing pieces that will solve the mystery.

From a lethal chemistry classroom to a fatal medical marijuana clinic to a deadly memorabilia convention, the evidence leads to Sin City's most twisted corners. Whatever the case, lead investigator D.B. Russell knows he can rely on the brilliance of blood-work expert Julie Finlay, and veteran investigators Nick Stokes, Sara Sidle, and Greg Sanders.