After Warrick is shot in a Las Vegas alley, the CSI team comes together to deal with the aftermath.

The CSI team is shocked and saddened when, after working with Dr. Raymond Langston (Fishburne) on the "Dick & Jane" murders, Grissom announces that his time as a CSI has come to an end and offers Langston a permanent position on the CSI team.

A casino employee is beaten and raped on her way home from work, but she survives and identifies her attacker. Unfortunately, a DNA test sets him free and Grissom must wrestle with whether evidence can ever lie. Later, Grissom comes to the rescue of a coworker who ends up on the other side of the law

As the CSI's continue their search for and discover the identity of the "Miniature Killer", Grissom and Sara's relationship gets exposed to the rest of the team as she goes missing during the investigation. The "Miniature Killer" is finally captured, but not before a member of CSI becomes the killer's final victim.

Nick takes the lead on a case where in the house a family of four, three pools of blood are found. Nick thinks that the little girl may still be alive, but Sara is doubtful, thinking that Nick's recent near-death experience is affecting his judgement.

A deer is illegally killed, and the person found with the body in the back of his truck apparently dressed it in a tutu. The man, who was completely drunk when arrested, was being interrogated by Nick and Brass, and suddently tries to escape and is pepper sprayed. Unfazed by the spray, officers then taser him and he bursts into flames and dies. Meanwhile an unbalanced woman wearing a tinfoil outfit at the front desk tries to warn people (including Nick) of an alien invasion. After observing the burning man, she later turns up dead with green-tinted blood. When other people turn up with the same problem, it's up to the team to figure out why. Meanwhile, an old couple dies, apparently in their sleep... but there is evidence the cases are related.

Catherine comforts Warrick when he is accused of murdering a famous Vegas gangster and even he is uncertain of his guilt or innocence.

When the team discovers a connection between a new murder and a serial killer, Grissom secretly joins the class of a criminal pathologist (Laurence Fishburne) to help crack the case.

Catherine revisits one of the very first cases she worked as a CSI when the convicted felon in the murder claims the verdict was based on faulty evidence.

When Nick, Greg and Hodges take Henry to celebrate his birthday at a biker bar, they uncover a double homicide and find several suspects still at the bar who may be the murderers.

The CSI team says goodbye to Catherine Willows as she makes a life-changing decision.

When a teenager and her sister are the sole survivors of the gruesome murder of four members of one family in a quiet suburban neighborhood, Grissom and his entire team investigate the crime. What initially looks like a bizarre cult murder becomes more disturbing when they discover the motive behind the massacre.

In the second part of this two-parter Grissom investigates the murder of an aging rockstar who is found dead in his kitchen with an exact replica of the crime scene on the counter next to him. Meanwhile, Catherine probes her own abduction and learns that someone may be targeting her family.

Grissom returns from his sabbatical; Keppler is put into a compromising position when the bodies of a Trenton police officer and a hooker are found in a hotel room. The man who found them is a retired New Jersey cop and close friend to Keppler, who doesn't reveal their relationship.

Once he unseals a package sent to him through the mail, Grissom is floored when he finds a miniature crime scene inside. The finding is entirely more perplexing since the successive killer accountable for earlier related miniature crimes is now deceased. Grissom plows to examine the miniature and discover the actual location, when the investigation makes it clear the murder showed has yet to happen, but is probably going to happen soon.

When a has-been boxer is killed, the CSIs must establish which of several life-threatening acts actually killed him.

Sara questions her future as a CSI when a past case comes back to haunt her, the 12 year old Hannah, who has to back up her brother one more time with all new tricks up her sleeves.

The world of illegal dog fighting is explored by Grissom and the rest of the team when they take on the case of a wealthy socialite who was murdered. Meanwhile, Warrick struggles to clear his name in the recent exotic dancer murder case.

Grissom and his team battle the flu when they are called upon by D.D.A. Klein to investigate the deaths of several key witnesses for a grand jury case against a dangerous Las Vegas gang.

A rising young star is killed in a wreck and her determined stalker claims credit, but the team finds out there's more to this tragedy than meets the eye.

Grissom's nemesis, serial killer Paul Millander, reappears and claims a third victim in this gripping episode. The latest slaying matches Millander's previous killings in that it recreates his father's murder. The killer's next target was born Aug. 17, 1956...which just happens to be Grissom's birthday.

Catherine is ordered by a kidnapper to accompany a man who is to deliver $1 million in ransom to him or else he will kill the man's mistress.

Grissom investigates the murder of two men that leads him to a new encounter with Lady Heather. Catherine is desperate to find out what lead to the near death of her daughter and why her ex, Eddie, disappeared.

Grissom and Warrick get the case of an old woman found mummified in her closet. Sarah and Nick arrive to investigate a breaking and entering to find a raped teen. These cases are not as disparate as they first seem. Catherine looks into a gun found by a boy. The gun is connected to a week old murder across town that Warrick caught.

The CSI teams come together to save one of their own when they learn one team member has been kidnapped and buried alive, and now they must find him before he suffocates under five feet of dirt.