The team is called to a suburban house where the whole family, except the two daughters, have been murdered with no apparent motive.

Sara and Grissom investigate the death of a woman, Kaye Shelton, found wrapped in a blanket in the mountains. With no way to confirm the time of death, Grissom relies on the insects found on her body to establish a timeline. Catherine and Warrick work on a case of a stolen painting. Nick works solo on a case of a missing wife.

Grissom receives a video tape from an inmate called Frank Damon who is on trial for the arson which resulted in his wife and son's death. On the tape, Damon claims that he is innocent and asks Grissom to help him. Grissom agrees to re-examine the evidence, despite knowing that this will anger Ecklie who originally worked on the case. Nick and Catherine, meanwhile, work on the case of a young man found shot in the head inside his car.

A bomb in a brief case goes off in the lobby of an office building. The team must piece together all the parts of this bomb to look for the maker's signature. Nick becomes involved in a crime after spending a night with a woman who ends up dead the next day.

The investigation of the death of a petty con man/drug mule leads the CSI team to Brass' daughter Ellie.

Grissom studies Ananda's Vegas Buddhist monastery where four Thai monks were fatally shot in the forehead. Forensics also show the presence of hostile restaurant owner Peter Hutchins Sr. and his son, Pete Jr. Eventually, possible theft is considered. Catherine's mentor Jimmy Tadero falsifies evidence concerning the case of violent repeat-offender Dwight Kelso, who maintains his innocence on his deathbed.

While in a dinner party to celebrate the retirement of Director of Robert Cavallo and the promotion of Conrad Ecklie, Grissom is summoned by Capt. Brass to investigation a homicide in the Olympia Hotel. He stumbles upon Ecklie's right hand Sofia Curtis in the elevator and they go with Brass to the suite where they see the body of the teenage Nicole Jensen next to vomit. Soon they learn that the suite was reserved by the hotel's owner Charlie Macklin for his daughter Janelle. The McKinley High School is giving a homecoming party in the ballroom, but Janelle is giving a private party in the suite. Catherine, Nick and Warrick join the investigation and interview the guests. They note that Janelle is missing and they learn that two masked kidnappers have abducted Janelle. When Catherien and Sheriff Atwater interview Charlie, he tells them that he knows his daughter and that was a prank to get his attention. The CSI team proceeds the investigation and find the truth of what happened during the night.

While giving his testimony in a retrial, Grissom sees fingerprints on a matchbox that he does not recall. The victim Max Larson was found dead I his hardware store hit by a wrench. He requests a recess to the DA and reopens the investigation of the case. He follows the protocol and assigns Catherine, Warrick and Nick to investigate the case again and why they have missed the fingerprint in their investigation. Ecklie asks Sofia to investigate Grissom's cases and begins a witch hunt in the laboratory. Meanwhile, Sara, Greg and Det. Louis Vartann investigate the case of a John Doe, who died after shooting his own leg. When they succeed to find the register of the gun, they find clue of another case.

Greg is doing his final proficiency test and he has a case to solve. Ironically, he investigates the death of a Sherlock Holmes- wannabe, obsessive to the point of recreating the great detective's living room in his home. He died from a close-range gunshot wound. The murder weapon is not found in the scene although everything other pieces of evidence suggest that it was a suicide. Working under Catherine, Nick and Warrick works on a case of a dead guy found in his car which veered off the highway. Dr. Robbins cannot find the cause of death and it is left to the two detectives to solve the mystery.

When a body is found at a construction site, Catherine, Warrick, Nick and Sara investigate the case. They dig the spot and Nick finds a third foot, indicating that there is a second body in the place. Grissom helps Catherine to get the bodies without damage out of the large block of tar using liquid nitrogen. Sara rebuilds the face of the upper victim with plaster and comparing the mold with photos of women victim of abuse, they identify her as Svetlana Melton. They interview Andrew Melton, her ex-husband that now is married with the Asian June. Meanwhile, Sara has a friction with Catherine and Ecklie suspends her, and asks Grissom to fire her.

When the wealthy casino owner Bruce Eiger is found dead on the front steps of his mansion, Ecklie assigns the entire team to the case. They investigate whether Bruce has jumped, felt or was pushed off the second floor. In the autopsy, Dr. Robbins finds that Bruce was sodomite, with repeated insertions into his rectum. When they find a secret compartment in Bruce's mansion, they are forced to understand the bizarre world of Infantilism.

When the flight attendant Martha Krell is found dead and raped in her hotel room, Grissom, Greg, Sara and Capt. Brass investigate the case. They note that there is no luggage in the room that was cleaned and sanitized without any evidence. Ecklie tells Sara that he had a similar case five years ago, with the flight attendant Sue Stein. Sara notes that the present technology is able to retrieve the fingerprint from the previous case. Meanwhile, Catherine, Nick, Warrick and Det. Chris Cavaliere investigate the case of the death of the twelve-year-old Ty Hawkins, who has been beaten to death on his bed while sleeping. His fourteen-year-old brother Matt becomes the prime suspect to Det. Cavaliere and when Matt confesses the murder of his brother, Nick questions the way Det. Cavaliere conducted the interrogation. The CSI team proceeds the investigation and finds two other suspects: Ty's father Martin and the homeless Walter. Who might be the murderer?

After a tough day at the work, Catherine invites Warrick and Nick to drink in a bar. She goes alone and meets Adam Novak, a stranger that fives his phone number in a matchbook. He offers to go to her car with her, they kiss each other and Adam turns brutal when she does not want to have sex with him. She hits her head on the door of the car and goes home. While sleeping, Catherine gets a call from Grissom and heads to the crime scene, where Alice Granger is found dead with a shot in her head. When Det. Vartann find her car nearby the bar where Catherine was, she goes with him to investigate. When she finds a matchbook in the belongings of Alice with a phone number, she heads home to find Adam's matchbook, but it has been thrown in the garbage. Their further investigation indicates that her ex-boyfriend, Jeff Simon, might be the killer, but he had a strong alibi. Catherine tries to tell to Grissom about her possible involvement in the case, but he does not give much attention to her. But when a second victim is found with the same M.O., they realize that the killer might be the same.

When the university students Paula Levine and Trip Wilmont are found dead on the floor after having sex in Trip's dormitory room, Grissom, Sara, Greg and Capt. Brass investigate the case. Grissom leaves the case since he has to go to the court and Sara and Greg use the monoxide carbon detector to look for a source, but they do not find any monoxide carbon in the room. Meanwhile, Brass talks to his next-door neighbor Zack Capola, who says that Trip and him were just mates, not friend. Sara and Greg proceed the investigation. Meanwhile, Catherine, Warrick and Nick join to David Phillip in the middle of a crop circle to investigate the death of a man. In the autopsy, they learn that the victim has urinated in his underwear. When the CSI team locates the owner of the helicopter that was in that area, they learn what has happened to Kevin Staniland. Meanwhile, Det. Louis Vartann finds that no investigator is available and Conrad Ecklie is forced to go with him to the Tangiers since there is a dead body needing to be processed. They learn that the victim is James Billmeyer from New Jersey and Ecklie requests the shoes of the woman that found the body since she stepped on the blood. When James' body vanishes from the morgue there is a further investigation.

While investigating a case, Nick is abducted and is buried alive in a special coffin while his team takes unorthodox steps to try to find him.

With its desperate attempt to ransom Nick's release failed by their enemy's fanatical revenge, the CSI team must use all their investigative talents to find Nick, whose perilous situation is becoming all the more horrific by the minute.

When a woman dies on her staircase, the team uncovers marital infidelity and an even bigger secret during their investigation.

Catherine investigates the murder of a young mother who claimed God got her pregnant, while Grissom witnesses a very shady trial.

The CSIs continue to process the evidence collected from the high-speed chase. They must also find the bullet which killed a police officer to determine who shot him.

Excessive smoke coming from a fire place alerts the fire department, which in turns calls the CSIs as a charred body is found inside the chimney. The body is burnt beyond recognition. A gym membership card found on the body identifies him as the son of the house's owner. The opportunity to search the house leads Catherine and Warrick to look for any evidence about a one-year-old disappearance of a young girl who was on her way to this house before she vanished without a trace.

In a courtroom, Det. Sofia, Dr. Robbins and Nick go to the stand to testify about the murder of the popular high-school student Stacy Vollmer, who was found wrapped in a shower curtain and buried in a flower bed in her school. The prime suspect is Marlon West, and all the evidences point to him. When his twelve-year-old sister Hanna goes to the stand and confesses the crime, the judge gives seventy-two hours to the prosecution to check the evidences to proceed the trial without reasonable doubt. Who killed Stacy Vollmer?

Gil investigates the murder of a rock star, which is complicated by the discovery of a miniature replica of the crime scene at the house. And Catherine tries to determine if she was raped after waking up nude in a seedy hotel.

While CSI tackles cases involving a teen beheaded in a go-cart accident and the murder of an iconic gentleman's magazine publisher, Ecklie confronts Gil and Sara about their concealed affair.

A mobster that Warrick had a run-in with is found dead, and Warrick is found at the scene with the murder weapon. However, he insists that he has no recollection of the crime.

CSIs past and present come together at the news of Warrick's death. But will Warrick's real killer successfully frame another police officer for his murder?

CSI is caught in a race against time to catch a failed artist-turned serial killer who is leaving his victims in unusual poses all over Las Vegas.

Grissom gets Dr. Langston's help to find the man who is carrying on the serial killer's work before the next victim is killed. The case will prove to be Grissom's last with the crime lab.

Dr. Langston has a challenging first day learning the ropes both in the field and in the crime lab, and the team has a difficult time deciding who will get Grissom's old office.

A case from Catherine's past is reopened when a man who has been in prison for 18 years challenges the evidence that convicted him.

A biker who is brutally stabbed to death in a biker bar turns out to be an undercover agent whose cover was blown.

Langston investigates a homicide which is connected to the discovery of rare valuable chips from a legendary casino from the 1980s.

A young Hollywood actress is killed in what appears to be a simple drunk driving collision, but the team soon suspects that there is more to the case than meets the eye, and a shootout in the crime lab may confirm their suspicions.

Two murders occur in a neighborhood being taken over by undesirable residents, and the prime suspect has a connection to a serial killer case from CSI's past.

When a police officer shoots and kills his ex-partner in a parking lot, the team must figure out whether it was premeditated and possibly racially motivated.

An unsolved case from Captain Brass's past reemerges when the mother searching for her missing family is hit by a car, but neither may be prepared for the disturbing answers that emerge in the case.

A dead reporter is found with pictures of the victims of "Dr. Jeckyll" on her, and the investigation into her death reveal some disturbing secrets about Dr. Langston, past and present.

The CSI team investigates a well-orchestrated bombing at the funeral of Officer Franklin Clark.

The deaths of a rancher and an engineer are tied together by their connections to a tainted water supply and the small-town newspaper reporter trying to expose it.

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.

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.

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.

Under the direction of new boss D.B. Russell, the team tackles cases involving a wild shootout on a tram car, and a body dumped in an alleyway.

The task of solving the grisly quadruple homicide of an entire family becomes more complicated when three people confess to the crime.

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.

Catherine goes into hiding with D.B. after Mark Gabriel's hitmen try to kill her, but they soon come to the realization that Gabriel himself may not be calling the shots.

While the team tries to figure out a team of wedding bandits' next target before they strike again, Morgan pretends to be David's girlfriend to impress his mother.

A vehicle explodes during an off-road race, and the team discovers that it may have been connected to a plot to kill an oil executive.

While at a campaign dinner for the Sheriff, the team are called to a triple homicide with a familiar victim.

While Ecklie fights for his life after the shooting, the team close ranks in preparation for McKeen's next move.

CSI investigates a massacre at a local diner, and the team suspects that one of the victims' stalkers is the shooter.

While working a foot patrol on the strip, the CSIs stumble on a murder victim, and a number of their suspects are already in police custody on lesser charges.

While investigating the death of a Cuban singer's sister, CSI discovers that the case may be tied to a feud between two Cuban families.

The team investigate a "locked room mystery" when a poker player is found murdered in an elevator, which he rode alone. Meanwhile, the search is on for a dominatrix who took a session too far.

CSI searches for a serial killer inspired by Dante's "Inferno," and Brass's daughter may be one of the killer's next victims.

The search for the serial killer who kidnapped Brass's daughter intensifies after Morgan become the killer's latest kidnapping victim.

The team has to put together the pieces when four dead bodies are found after a fire in a music club during a hate core concert.

The team gets a second crack at a reclusive millionaire who may have gotten away with murder 14 year earlier when a new dead body is found in his home.

A cannibal is on the loose in Las Vegas, and Ecklie begins to contemplate his future as sheriff.

The CSIs investigate the cyber-related murder of a prominent casino owner's wife and receive help from the FBI's Cyber Crime Division. Patricia Arquette guest stars.

The discovery of a dead body rekindles a 25-year-old mystery involving a robbery and a dead boy, and an amateur forensic investigator helps crack the case. Meanwhile, Brass's daughter is in the hospital after an overdose.

Russell and Finlay must confront a serial killer case from their past while working in Seattle when a copycat killer suddenly emerges in Las Vegas.

CDC may be dealing with a potential deadly virus outbreak in Las Vegas, and Sara and Greg may have been exposed to the virus while investigating a crime scene.

Brody, Sidle and Finlay try to relax at a forensics conference when a mass shooting occurs on site.

The team discovers that a murdered prisoner who was informing from the inside to the police had a second job informing for the Feds.

The CSIs investigate a murder that's linked to the kidnapping of two teen girls.

A final showdown between the CSIs and the Gig Harbor Killer, whose motives are revealed. Meanwhile, Nick Stokes makes a decision that affects the team moving forward.