A man accused of murdering his wife and co-workers leads the CSIs on a wild ride through a busy casino, eventually barricading himself and a hostage in a casino hotel room. The CSIs process the evidence from the crime scene to determine whether or not the man acted alone or had an accomplice. One of the CSIs eventually steps in as a hostage negotiator, putting himself in danger.

While investigating an elderly woman's murder, Grissom receives a miniature crime scene replica; Greg attends a hearing to ascertain his culpability in a teenager's accidental death.

The CSI's investigate a series of deaths related to an energy company's grotesque cover-up of tainted water.

When five people are killed in a small plane crash a mile off the Vegas strip, the CSI team is called to investigate. Also, Sara feels the strain of having a long-distance relationship with Grissom when a former lover of hers is involved with the crash investigation