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.

Two men are found murdered after scamming Sam Braun's casinos. Grissom and Warrick investigate after Catherine is thrown off the case. One of the suspects is the son of a man Braun caught cheating. Nick gets the promotion that Sara coveted.

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

Catherine, Nick, and Warrick investigate a badly mutilated body in the woods. The cause of death was a shotgun blast. Nearby is a beaver dam made in part with cash. Grissom, Sarah, and Nick try to determine how a man was killed in a hotel room. It leads them to a convention of big women.

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.

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.

The two forensic teams come back together under the leadership of Grissom and Catherine just in time to tackle three separate investigations: a murdered couple found in bed in a suspicious trailer explosion; a beautiful stripper discovered dead and dumped in the worst part of town; and two bodies found baked and decomposed after spending five days in the trunk of a car exposed to the hot Vegas sun, forcing the CSIs to ""wrap"" up the evidence and bring it back to the lab for further analysis.

In part one of this two-part seventh season opener Grissom and Catherine handle the case of a women's dead body found at Cirque du Soleil by a performer. Meanwhile, an investor at one of Sam Braun's new casinos is shot to death during a party on the rooftop. Catherine's life is in jeopardy after visiting a nightclub with Nick. Grissom finds a miniature replica of a crime scene that he is investigating.

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.

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.

Hodges stages hypothetical murders in the lab in order to give his fellow lab techs a chance to play CSI, but unbenownst to them he has other motives behind his actions. Meanwhile, after Sara's farewell, everyone tries to comfort Grissom.