99. Formalities - November 11, 2004

Guest starring: David Berman, Xander Berkely, Joseph Patrick Kelly, Louise Lombard, Jon Tenney, Jonathan Banks, Danica Stewart, Kate Mara, Kevin Cooney, Nicole Lenz, Ty Upshaw, Marc Vann, Larry Sullivan

The CSI team investigates the death of a high-school student at a private party in a hotel suite upstairs from the school's homecoming dance.

Grissom works with a CSI from the dayshift on the murder and apparent kidnapping case of two high school classmates attending their formal held at a Vegas casino.

Louise Lombard ("Hidalgo") guest stars as a dayshift CSI working with Grissom. Xander Berkely ("24") returns as Sheriff Atwater and Jon Tenney ("Brooklyn South") guest stars as the father of a kidnapping victim.

Grissom abruptly leaves a dinner honoring Conrad Ecklie's (Marc Vann) appointment to new Assistant Director of the Crime Lab after he gets an urgent page to rush across the street to a hotel suite where a high school student was found dead. Dayshift CSI Sofia Curtis (Lombard) assists Grissom with the case. The autopsy reveals that the victim died of suffocation after one of her classmates was kidnapped from the party. The CSI team now races to find the kidnapped victim before she is found dead, too.