A kidnapping case becomes unusually personal to the usually detached Grissom. The 4-month old baby, Zach Anderson, was allegedly kidnapped from his home. A ransom note, found by his mother, is left in his crib. Many things seem strange about this case as more evidence are analyzed. When Zach's body is found on a nearby golf course, the team is sure that his death is no mere accident.

A scuba diver (at least a man who dresses like one) is found dead, fully equipped with an oxygen tank, on a tree in a burned forest.

A body is found in the body farm. He died from what looks like a bullet wound, yet Dr. Robbins and Grissom can't find any bullet fragments. Instead, they found bits of ground beef inside the wound track. The team links this death to an arson case. The investigation takes a turn when the 12-year-old daughter of the deceased's fiancée has been a victim of sexual assault for some time. Back at the lab, Sara asks for a 6-month leave, citing that she doesn't feel at ease at work with her co-workers, especially with her boss, Grissom.

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.

When a group of bird watchers sees a raven with an eyeball in its nest, the CSI team investigate the case. They trace a radius from the nest and using the evidences, they find the location where the corpse may have been dumped. Catherine, Sara, Nick and Capt. Brass find the body and they identify the body. The prime suspect is the ex-husband of the victim. Meanwhile, Grissom, Warrick and Dr. Robbins find that the car seller Fred Stearns is not dead but dies later. They suspect that one of his colleagues may have killed him.

Several couples are killed bloodily after a wild party night in the same luxury hotel with Cameron and Mandy Klinefeld, or rather one somehow forced to kill the spouse. Nick is pleased to bump into former college mate Kenny Richmond, who works there, until it seems buddy boy passed confidential information to the press, which could get Nick fired.

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.

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.

A man is observing the sky with a telescope when, out of the blue, he is burned by a blaze. Grissom and Sara arrive to investigate the scene when Grissom finds a woman still live but completely burned. They believe it was arson and Sara uses the fingerprint in a broken bottle of cheap vodka to identify the truck driver Patrick Bromley. Meanwhile, Catherine, Warrick, Nick and Capt. Brass investigate the murder of the Stewart family, where the parents were shot and their five-year-old daughter Dani drowned in the swimming pull. Nick believes in the murder-suicide theory while processing the evidences. When they learn that the DNA in both cases belongs to the burned woman, they realize that the cases are the same.

A pedophile arsonist maintains his innocence in the disappearance of two young boys, but he is also willing to help the investigation by giving Grissom insight on the potential kidnapper's mindset.

A death in a drive-by limo shooting and the dragging death of a young woman turn out to be related crimes, and Greg discovers that the brother of the young man he ran over may have been involved.

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.

The homicide of a weathercaster who was moonlighting as a prostitute uncovers a clue that could lead Dr. Langston to the missing woman from his New York and Miami cases.

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.

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.