During a routine traffic stop, a police officer is murdered and now Horatio and the team must track down the killer. The only witness to the murder is a civilian who was doing a ride-along with the officer, but who is now missing. Roadside evidence leads the CSIs to Missy Marshall, a teenage girl who was with the killer at the time of the murder. However, as the team searches for the civilian and the killer, they find that Missy may have been more involved with killer and the shooting than she is admitting. Meanwhile, Horatio and Rebecca's relationship is in jeopardy when they don't see eye to eye on a case.

An extreme skateboarder and videogame tester is found dead on a half-pipe platform used to program extreme skateboarding video games. The CSIs discover that he was wearing reflective sensors when he was killed, so the motion-capture device used to produce these videogames recorded the murder as it happened, but not the murderer. Now the team delves into the highly competitive world of videogame programmers and testers to find the killer.

Three suburban housewives on a girls' weekend in Miami are the prime suspects when the hotel's handsome pool boy is found murdered. When Horatio is tipped off that his team is facing a surprise efficiency review, he must trust Calleigh, Delko and Ryan to work together to find the killer. However, when they independently follow the evidence, each discovers that their analysis points to a different killer.

The CSIs investigate the brutal murder of a man who was learning how to pick up women at a hot nightclub. Meanwhile, Horatio tries to help out Marisol, Eric Delko's sister, who was arrested on drug charges.

Lifestyles of the rich and famous come under the CSI microscope when a wealthy family's nanny turns up dead.