CSI: VEGAS opens a brand-new chapter in Las Vegas - the city where it all began. Facing an existential threat that could bring down the entire Crime Lab and release thousands of convicted killers back onto the neon-lit streets of Vegas, a brilliant new team of investigators led by Maxine Roby must enlist the help of old friends Gil Grissom and Sara Sidle. This combined force will deploy the latest forensic techniques to do what they do best - follow the evidence - in order to preserve and serve justice in Sin City. In the premiere episode, an attack on Jim Brass (Paul Guilfoyle) kicks off a twisted conspiracy targeting the Las Vegas crime lab.

Gil Grissom and Sara Sidle come to the aid of a former colleague who is implicated in tampering with evidence. Maxine and the rest of the CSI team work the murder of a couple slain on their wedding day, following the evidence to the salacious underbelly of the Las Vegas elite.

Grissom and Sara's investigation into charges against David Hodges heats up as Internal Affairs joins the hunt. Also, pressure rises for the CSIs when a video game developer's body is found floating in a fountain before a huge gaming tournament.

The CSI team investigates when a body is dug up in the luau pit of a Hawaiian-themed hotel. Also, Internal Affairs begins to question Grissom and Sara's return to the crime lab.

As Grissom and Sara close in on who framed Hodges, the CSI team investigates a lock room murder mystery at 30,000 feet, when a cargo plane lands autonomously at McCarran Airport and everyone on board has been killed.

Max puts CSI on lockdown when evidence in a new murder tips Grissom and Sara to a new suspect in the crime lab. Also, Folsom and Allie investigate a series of chilling killings at a dilapidated clown-themed hotel.