Catherine heads to a small town in Nevada ("Leaving Las Vegas") as Grissom and Sara continue their affair ("Living Doll"), in the seventh season of CSI. Supervised by Grissom and Willows, the Las Vegas Crime Scene Investigators face both personal and professional challenges as Grissom says goodbye, and new CSI Michael Keppler joins the team ("Sweet Jane"), as they investigate the bizarre, the brutal, and the unprecedented, including a chainsaw massacre ("Toe Tags"), a death at a church ("Double-Cross"), a kidnapping ("Burn Out"), a series of miniature killings ("Post Mortem"), the death of identical twins ("Happenstance"), and the return of a 1970s Mob Boss to Vegas ("Living Legend"). Meanwhile, Catherine faces the loss of her father ("Built to Kill"), Greg is assaulted ("Fannysmackin'"), Keppler faces his past ("Law of Gravity"), and the team attempt to hide their amusement when a man is found trapped in concrete ("Loco Motives").
