A Jane Doe is brutally attacked and raped before being left to die on the side of the road. With two bullets lodged in her brain, she is in a deep coma. Catherine and Warrick work on an open case of a man killed by his neighbor. The statements from the accused and the deceased's wife contradict each other.

Tony Braun, the son of Las Vegas mogul Sam Braun, is found dead in his home, apparently victim of a drug overdose. But as the scene lacks all evidence normally connected to an overdose, the team soon suspects murder.

The death of a woman named Mona whose body was dumped in a sand pit leads Grissom and Catherine to a fetish club run by Lady Heather. Since Mona was a dominant, Lady Heather was surprised that her employee was tortured and suffocated to death. This leads Grissom to conclude that the victim was a 'switch', someone who could play both the dominant or the submissive role.

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

When a young woman riding a horse finds a body of a woman inside a pipe in a construction site, Grissom and his team investigate the murder. Soon they find another woman's body and coroner Dr. Albert 'Al' Robbins notes that the women are very different despite being sisters. Their further investigation indicate the Donna Marks was a reclusive woman, maybe agoraphobic, while Joan Marks had a different behavior. Meanwhile, Catherine and Nick investigate the murder of the hunter James Jasper in the woods. James was an insurance broker and an experienced hunter, but was not wearing the safety vest. Catherine, Nick and Detective Vega learn that Jasper and his wife Linda had lost their jobs. When they find a one-million dollar life insurance on behalf of Linda, his wife becomes their prime suspect.

Boxer LaRoi Steele didn't survive his third fight against Javier Molina, whom he defeated in both earlier encounters. Grissom works out what happened exactly and why after learning how that Vegas show discipline really works. Nick wanted a solo case but isn't tickled-pink with a jewelry theft, yet does it well enough to counter abuse from ingrate victims. A gang fight involving an arrogant 'modern' gangster turns out to tie in as well.

Matt Phelps sends his two kids to bed, and out of the blue, there is a drive-by shooting and his daughter Aimee is shot and killed in her bed. Grissom, Warrick and Capt. Brass investigate the case and Grissom learns that Matt Phelps is Warrick's mentor and friend. Warrick's investigation is conducted based on his emotions instead of on the evidences with serious consequences for Matt and a suspect. Meanwhile, Nick and Sam Vega investigate the mysterious death of a boss of a four-men Internet service company in the air-conditioned servers' room. They find many secrets in the team but no suspect and no murder weapon. Until Nick observes the duct of the air-conditioning.

When a body is found in a foam party, he is identified by Grissom and Capt. Brass as the male prostitute Trey Buckman. Meanwhile, Catherine and Nick investigate a decomposed body of the also male prostitute Croix Richards in his apartment. Catherine receives a phone call from Eddie's phone, who is with Lindsey, with poor reception, but soon she learns that Lindsey is screaming and she leaves the crime scene to seek out her daughter. She finds Lindsey in a car in the water but she rescues her. Sara and Det. Vega investigate the case and they suspect that Eddie is dead. Meanwhile Grissom concludes that both victims may have been dead by insulin and they were employees of Lady Heather. Grissom and Catherine visit the suspect Rebecca and meet her husband Steven McCormick that tells to them a weird story. Then he goes with Capt. Brass to Lady Heather's house. Grissom has a personal moment with Lady Heather and when he learns that she is diabetic, he requests a warranty to get her insulin.

A really badly decomposed body of a man is found in a chemical waste barrel. The markings on the barrel indicates that it came from a warehouse, now used as an arena for specially-built remote-controlled robots to destroy each other.

The discovery of a dead man in the wilderness in a fursuit leads to an investigation at the goings-on at a furry convention.

Teenager Brian Haddick is found on a construction site, skull fatally smashed, with an employee's hammer. Grissom's team checks on the construction crew as well as Brian's school crowd, stumbling on abused love and dirty practices. Another victim was killed by a bullet which literally fell from the sky.

When a delivery boy finds a severed head with the hair ripped off inside a newspaper stand, Catherine, Nick and Det. Sam Vega assume the case. In the autopsy, Dr. Robbins pull out a snake from her mouth and finds the serial number of her bridgework. The victim is identified as Veronica Juarez, and the investigators find a diploma from a university on the wall. They believe she is a gangbanger and they see a poster of the band Extremo. Nick and Det. Vega visit the club where Extremo is playing and they identify the victim as Carla. Soon they learn that the song that Extremo is playing is a ten-year-old narcocorrido that describes the way Veronica was murdered. Meanwhile, Greg, Sofia, Warrick and Capt. Brass investigate the murder of a man wearing and expensive suit shot in the head in the driver's seat of a handicap van. They identify the victim as Vincent Decarlo and they find that the victim was shot from a wheelchair. Soon they learn that the wheelchair belongs to Bonnie Bakerset, who lives in a nursing home, and a nice salesman has sold many things to Bonnie that has just died.

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.

A psychic is murdered in her own shop after predicting her own death.

The death of three unidentified teenagers lead the CSIs inside the world of rap music.

A well-known Las Vegas humanitarian is killed for her involvement in a dog-fighting ring, and CSI searches for clues in the strip club murder that Warrick was framed for.

A woman's unlikely suicide is tied to a bank robbery and a hypnotist, the team investigates the murder of a guidance counselor who was also a degenerate gambler, and Sara helps out in an euthanasia case.

While investigating a gang-related shooting in an otherwise quiet suburban neighborhood, Raymond and Riley are held hostage.

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

When the CSI team investigates three seemingly unrelated murders, they discover someone is getting revenge for cold case murders that were never solved.

A killer is about to go free because of a dirty cop, so the team tries to connect him to an earlier crime to keep him in jail.