Season synopsis
Contains spoilers for this season and earlier seasons.
Season 5 changes the Crime Lab’s working shape. Greg Sanders is eager to leave the DNA lab for fieldwork, while an unexplained fingerprint discovered during Grissom’s courtroom testimony forces the team to reopen a case and puts Grissom’s supervision under scrutiny. Conrad Ecklie investigates the lab and ultimately divides the night shift: Catherine leads Nick and Warrick, while Grissom works with Sara, Greg and day-shift CSI Sofia Curtis. Greg passes his proficiency test and earns a place in the field, even as the investigators keep encountering cases with evidence that initially seems impossible to place.
The season’s investigations include a thirteen-year-old girl’s kidnapping, the return of the Blue Paint Killer, a neglected child found dead in a storage bin, a severed head containing a snake, and the death of a casino owner whose private life surprises the team. Brass travels to Los Angeles after Ellie asks for help finding her missing friend; with Warrick’s help, he finds the killer but cannot bring him to trial. In the two-part finale, Nick is abducted from a crime scene and buried in a glass coffin. The kidnapper, Walter Gordon, demands ransom, then blows himself up before revealing Nick’s location. Catherine helps fund the ransom; the team pieces together the evidence and finds Nick alive, close to suffocation.
Gordon’s daughter Kelly is serving a sentence for accessory to murder. Her former work at a garden center and Grissom’s identification of the fire ants attacking Nick help locate the coffin. Even then, explosives beneath it make lifting Nick out dangerous. The team gets him clear, and Grissom asks Ecklie to restore his divided unit. Nick later visits Kelly in prison and urges her not to carry her anger with her when she is released.