Episode 1: Viva Las Vegas

Greg Sanders is taking his field proficiency test on a nightclub shooting, with Grissom judging his work; Nick and Sara investigate an alien body found in a shallow grave in Area 51; Warrick walks a mile in a dead man’s shoes to figure out why he committed suicide; and Catherine investigates the bloody murder of a stripper who died in bed with a tourist who doesn’t remember a thing.

 Guest Stars: Reiko Aylesworth (24) and French Stewart (Third Rock from the Sun)    

Episode 2: Down the Drain

After a flash flood, drains clogged with human bones lead Catherine and Warrick underground, where they find themselves in a compromising situation; Greg donates his body fluids to science; and an untimely explosion jeopardizes the CSI team.

Episode 3: Harvest

Vegas is on an “Amber Alert,” as the CSI team races to find a missing 12 year old girl, but the kidnapping turns even more complicated – if they don’t find her, her brother who needs his sister’s kidney to live, may die; and Greg may have found a worthy replacement for himself in the DNA lab.

Guest Star: Aisha Tyler (Friends), D.B Woodside (24)

Episode 4: Crow’s Feet

Catherine and Nick investigate the death of a woman who was searching for the Fountain of Youth; Greg and Sara try to solve the ultimate “locked room” mystery, when a man is poisoned while his house is being tented by an exterminator.

Episode 5: Swap Meet

Sara and Greg investigate a swingers’ party when one of the revelers is found dead in a fountain; Nick and Warrick tackle the gruesome murder of a mini-mall owner who meets the wrong end of a table saw; Greg and Hodges compete for Mia’s attentions.

 Guest Star: Aisha Tyler as new DNA technician Mia Dickerson

Episode 6: What’s Eating Gilbert Grissom?

A human tooth is found in a festering pile of maggots and wood chips on the WLVU campus, leading the CSI team to investigate sadistic ritualistic multiple homicides with the familiar modus operandi of the “blue paint killer” – who’s already been executed for his crimes.

Episode 7: Formalities

Louise Lombard (Hidalgo) is introduced in the recurring role of CSI Sophia Curtis; Jonathan Banks (Wiseguy) guest stars as Bobby Jenson, and Jon Tenney as casino owner Charlie Macklin.

Episode 8: Ch-Ch-Changes

Real life transsexual Calpurnia Adams, whose story was told in the film Soldier’s Girl, appears in this episode as the member of a support group; Lindsay Crouse guest stars as therapist Dr. Mona Lavalle.

Episode 9: Mea Culpa

When a technicality brings Grissom back to court to testify in what he thought was an open-and-shut case from five years ago, he discovers new evidence – a fingerprint he may have overlooked which doesn’t match the defendant. This triggers a new investigation, indicting Grissom’s work on the case, and giving Ecklie a chance to nail him; Sara and Greg investigate the questionable shooting of a John Doe.

Episode 10: No Humans Involved

Grissom and his team investigate the shooting of a suspected drug dealer, which looks like a straightforward single murder but soon turns into a tragic triple homicide, including the death of an emaciated five-year-old boy; Catherine, Warrick and Nick look into a messy prison murder in an over-crowded holding cell after guards and inmates tangle..

Episode 11: Who Shot Sherlock?

Greg’s in the hot seat for his “final” proficiency test when a Sherlock Holmes aficionado’s apparent suicide turns out to be murder, and the case is a little less elementary than he would have liked; Warrick and Nick are not satisfied when they can find no evidence of foul play or cause of death when a motorist, who may have been stoned, flipped over an embankment.

Episode 12: Snakes

A decapitated woman’s head is discovered in a newspaper dispenser and when Dr. Robbins does his postmortem he finds a startling clue – a dead snake resting in the victim’s mouth; a man is found dead in a handicapped-accessible van, but he’s not handicapped; and Sara and Grissom finally address their relationship.

Episode 13: Nesting Dolls

Two bodies buried together and encased in tar are exhumed at a construction site; after a heated argument with Catherine, and an explosive meeting with Ecklie, a suspended Sara finally is forced to tell Grissom how she feels about everything --- including him.

Episode 14: Unbearable

 A young mother is reported missing by her husband; two bodies are found in the woods, one, a mauled hunter, and the other a desecrated Kodiak bear not native to the area that’s been shot to death.

Episode 15: King Baby

It’s all hands on deck when a high profile and much-hated casino mogul with a strange secret is found dead in his driveway;

Episode 16: Big Middle

Nick and Catherine investigate the death of man killed by a sawed-off shotgun; Grissom and Greg investigate when a man is found asphyxiated in a hotel room during a plus-size convention.

Episode 17: Compulsion

The CSIs respond when a flight attendant is found raped and stabbed to death in her cleaned and sanitized hotel room; a little boy is beaten and murdered in his own bed.

Episode 18: Spark of Life

The CSIs think they have found a woman burnt to death in a fast-moving arson fire, until she opens her eyes; a little girl drowns in the family pool, leading the team to discover her mother and father murdered inside the house, in what looks like a double-murder suicide.

Episode 19: 4 X 4

It’s a busy twenty-four hours in Las Vegas for the crime scene team: Grissom works a case in which a stolen Hummer is involved in a hit-and-run; Warrick investigates the murder of a model who was working a car show; Greg and Sara need to be hosed down by Haz-Mat when the case they are working turns toxic; and Nick tries to figure out who killed a schoolboy and dumped his body on a bus stop bench.

Episode 20: Hollywood Brass

Brass asks for emergency leave to help his daughter Ellie in Los Angeles – a friend of hers has disappeared, and the police are not particularly motivated to begin a search for a missing hooker, based on the word of another one.

Tony Award-winning actress Donna Murphy guest stars as homicide detective Captain Annie Kramer, a former colleague.

Episode 21: Committed

Grissom, Sara and Brass respond when a patient is found murdered in a mental hospital for the criminally insane with another inmate sitting nearby, covered in blood.

Episode 22: Weeping Willows

A lonely and frustrated Catherine meets the wrong man in a bar, but doesn’t admit to the encounter, even when he turns up as the lead suspect in what may be a double homicide.

Alan Rosenberg, Marg Helgenberger’s real-life husband, guest stars as Adam Novack and Anita Gillette guest stars as Catherine’s mother.

Episode 23: Iced

Two students from WLVU are found dead after a night of lovemaking, and Sara and Greg have to figure out how they died and if it was murder; Warrick and Catherine report to the scene where a blindfolded dead man is found in the middle of a crop circle; Ecklie is the only one left to work the scene at the Tangiers, where a tourist is found dead in the parking lot – and then goes missing from the morgue.

Episode 24: Grave Danger

This time it’s personal…one of their own is kidnapped and buried alive, and a reunited CSI team must race the clock to save him, in a special two-hour season finale. John Saxon, Andrew Prine, and Lois Chiles Guest Star; Cameo Appearances by Tony Curtis and the late actor/comedian Frank Gorshin, in his last acting role, playing long-time friends of casino owner Sam Braun