When CSI Mac Taylor decides to surprise his girlfriend in Vegas, he discovers she's missing and asks his friend D.B. Russell for help. Meanwhile, the CSIs investigate the loss of a local wine collector on part one of a two-part crossover with CSI:NY.

Sara is a lead suspect in an investigation after a brief encounter with another man in which she was the last person to see him alive. Also, her separation from Grissom begins to take a toll.