Because Warrick naively assumed simple uniformed cop Hal Watson would have arranged a search warrant, the crucial weapon in the rape and murder trial on a neighbor against Michael Fife is dismissed as evidence in court. A.D.A. Jeffrey Sinclair can only get a 24 hours delay to present new evidence to build the case again. Nick brilliantly smooths emotional waywardness from Sarah and Warrick. New clues expected to reconstruct the case against Fife actually indicate he's probably innocent. An alternative culprit must be found, starting from Fife's car where the bloody knife was planted.

When the nurse Debbie Marlin is found murdered in her bathroom, the CSI team investigates the case. They learn that Debbie was a promiscuous woman that used to date doctor. Her last boyfriend Dr. Michael Clark is missing and becomes the prime suspect of murdering her. However, their further investigation finds pieces of his body in plastic bags in several trash bins in an alley. Dr. Robbins concludes that the cuts have been made by a surgeon using probably a scalpel.

While trying to pass a bus on the highway, an arm strikes the windshield of the car of a couple. Catherine, Nick, Sara and Capt. Brass investigate the crime scene and find pieces of a woman secured by white strips of clothes on the bottom of the bus that was carrying inmates from a prison to a church. They believe the woman was trying to flee from the correctional facility. Soon they learn that the victim is Antoinette "Baby Girl" Stella that would be released on the next month. Sara and Nick go to the prison to try to understand why Baby Girl decided to escape. Meanwhile, Grissom and Warrick investigate the murder of Adanto Adams who was stabbed to death at the home of his intellectually disabled brother Zero. Soon they meet Zero and his guardian Frank Samuels and they learn that Adanto has promised to his beloved brother Zero that they would be rich. Warrick gets the videotape of the casino where Adanto went to play blackjack and lost a fortune.

When a roller coaster derails in an amusement park, there are six victims in the parking lot. Grissom, Nick, Sara and Capt. Brass investigate the case and soon they find that five deceased persons were in the train, but the employee Jim Nevins died twenty-hours before with a head trauma. Grissom interviews the park chief engineer Woody and learns that the old roller coaster has good maintenance. Grissom shows a nut to Woody and he says that it would be impossible to cause the train derail since there are eight sets that would have to lose. Meanwhile, Catherine and Warrick investigate the murder of the thirteen-year-old Tessa Press that was found murdered but not raped. Her mother Raina tells them that Tessa used to go to the house of a friend twice a week and she had assumed that her daughter was with her friend. Now they need to find what has happened to her.

Dr. Robbins concludes that a woman covered with red blotches has not died of Ebola. In the autopsy, he learns that the woman is Julie Stern, who was recovering in the hotel from a cosmetic procedure. He also tells to Catherine that she had urine in her stomach and signs of heavy metal poisoning. Catherine and Nick interview her doctor, Tony Malaga, who owns an expensive clinic. When Dr. Robbins finds the same symptoms in the autopsy of Renita Loakes, they return to the clinic with a warrant to get their medical information. Meanwhile, Grissom, Sara, Greg and Capt. Brass investigate the death of Elliot Beckman, whose house was fumigated and his body was found inside. The exterminators tell them that the house was supposed to be empty when they released the gas.

When the body of Vanessa Keaton is found drowned in water fountain in a gated community and hit on the forehead, Grissom, Sara, Greg and Capt. Brass assume the investigation. Soon they learn that Vanessa was in a swingers' party, but the water in her lung is not from the fountain. They interview the owners of the house and guests and collect the water in the swimming pools to see if any of them match the water in the lungs of Vanessa. Mia examines the DNAs in the several condoms in the garbage bin. Meanwhile, Warrick, Nick and Det. Chris Cavaliere investigate the murder Mr. Basengi, the landlord of a video arcade. They find an eviction notice to the tenants are Melissa Poolie and Charlie Pinscher that become prime suspects. They visit Charlie that tells that Melissa was his girlfriend and left him with the rent. They learn from Marty Gleason, a member of the crime scene cleanup, that the place has a decomposed smell and Warrick and Nick find the body of Melissa hidden in a game and Charlie is brought back to the interrogation room.

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?

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