A prostitute is found dead at the same site where a staged photo of the same dead person was taken and posted on a website days earlier, and Hodges theorizes that the parts on his new motorbike were in a fatal accident.
While the team searches for a killer who is killing his victims with an electric chair, Greg falls for a classic film noir "femme fatale" who may be connected to the case.
The death of a prominent professor in the deaf community is connected to a feud between two deaf graduate students competing over a grant, and the investigation creates tension between Sara and Grissom's mother.
CSI investigates the discovery of a dead body with cremated remains in his mouth, and whose body parts were cut up and placed in thrift store boxes. Meanwhile, Langston's ex-wife comes to him with a surprise announcement.
Dr. Langston confronts Nate Haskell one more time during his murder trial. Meanwhile, Nick faces an old teenage nemesis, Jason McCann, who is seeking revenge for his brother's death.
When two people who were thought to be dead come back to life, the evidence leads CSI back to a discredited ex-professor who conducted bizarre death-related experiments in the 1970s.
After a cop convicted of killing his police officer wife is killed in prison, the team discovers that he may have been framed, and Brass and Vartann may have been romantically linked to his wife.
With a suicide, a homicide, and an accidental death already in the books, the team places bets on whether there will also be a natural causes death to complete "the cycle" before the end of the shift.
Dr. Langston turns to Lady Heather for help in the murder of a woman who acted like a cat, and Nick tries to figure out what caused a pregnant teen to commit suicide after he saves her baby.
While the team discovers body parts of a man and a woman in a barn, a ransom video involving one of Nate Haskell's brides arrives at the crime lab. They soon discover that the two cases are actually connected.
Dr. Langston kills Nate Haskell, but was it murder or self-defense. Meanwhile, a closer look at the crime scene reveals details about Haskell's twisted past and his descent into a serial killer.
A sadistic killer from Sara's past who recently got out of prison appears to have struck again, while another dead body appears to have drowned in chocolate.
The former Las Vegas mayor is shot during the grand opening of a new mob museum, and a maid is killed in the hotel room of a chauvinistic Middle Eastern prince.
Morgan's life may be in danger when an injured man, who is also a suspect in the murder of two gang members, hijacks his medivac helicopter and demands to be flown to Mexico.
The murder of a popular sideshow performer sends the team behind the scenes at a carnival freak show. Rachel is found sadistically slain, the team goes behind the scenes of the carnival freak show to find her killer.
When the CSI team investigates three seemingly unrelated murders, they discover someone is getting revenge for cold case murders that were never solved.
As CSI and the FBI work together to solve the murder of a gunrunner working for a private defense firm, they discover that hundreds of very dangerous black market weapons may be out on the street.
When a genealogist is found dead in Dr. Robbins' bed, the team works on the theory that his wife may have been cheating even though she maintains her innocence.