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, and 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. Meanwhile, Horatio and Rebecca's relationship is in jeopardy when they don't see eye to eye on a case.

When the CSIs find a woman swallowed whole and killed by a gigantic snake, they uncover a covert drug smuggling operation. Evidence leads Horatio and the team to a drug smuggling operation where large snakes are suspected of being used to bring illegal drugs into the country to avoid detection by customs. However, when Horatio finds that Clavo Cruz, a nemesis of Horatio's who hides behind his diplomatic immunity, may be behind the operation, the team must find a legal way to put the criminal behind bars. Meanwhile, Calleigh and Wolfe investiagte when two women each claim that they are the real victim of identity theft and the other is the culprit.