Grissom and crew are called in after high roller Tony Braun, a known drug addict, is found dead in his house by a gardener. Since drug paraphernalia is discovered near his body and it is also determined that he had recently inhaled heroin, the cause of death is at first thought to be an overdose. But further examination of the corpse reveals that Braun had been restrained at some point with duct tape, leading Grissom to believe that the victim was forced to ingest lethal amounts of heroin and, perhaps, other drugs.

Things get personal for the CSIs in the top-rated series' third-season finale, which explores the intersection of the investigators' work and their personal lives. Three masked bandits steal a safe-deposit box from a Las Vegas bank in a daring daytime heist, during which Det. Lockwood is killed. Lockwood's death provides Grissom and his crew with added incentive to find the murderous culprits. But the case really hits home for Catherine when the evidence leads to casino owner Sam Braun, who is like a father to her. Also, Grissom's hearing gets progressively worse and he seeks out Dr. Robbins for help.

Two couples meet in a bar and one of the couples is murdered. When a second couple is murdered in a similar fashion the team suspects a pair of serial killers are on the loose. The case is complicated by leaks to the press and a judge reluctant to issue a warrant. Catherine gets some troubling news about her father's murder trial.

A severed head is shipped to Dr. Robbins from Jackpot, Nevada. Grissom goes to Jackpot to find the rest of the body and gets very little cooperation from the locals. Catherine gets an unexpected gift from her father.

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.

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 CSIs crash an elegant party for the city's crème of the crème to discover who killed a young man. The case gets a bit more personal for Catherine when her father, Sam Braun, is one of the suspects.

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.