Stella and Danny investigate when a jewellery designer is found dead, wearing the eight million dollar bra he created, and investigate the model he had shot and her bodyguard. Aiden begins to take the rape case she has been working on a little too personally, and is determined to stop the man before he can rape again. Hawkes gets to go into the field for the first time as he assists Mac in investigating the death of a man who liked to climb skyscrapers.
Stella and Danny are heading into the world of cuddle parties: non-sexual events were adults learn to touch and hug each other. Meanwhile, Mac, Hawkes, and Flack investigate the death of a hated plastic surgeon found covered with lye with thousands of eyewitnesses during rush hour at Grand Central Station. While Mac and Stella assist Aiden in a rape case, after she breaks an evidence seal, Mac must come to terms with Aiden's action and work up the nerve to fire her.
Mac and Danny look into the mysterious death of a man torn apart by tigers at the Bronx Zoo, which leads them to both the dead man's meat packing plant as well as his mafia relatives. Hawkes and Stella are left with the case of a beautiful young debutante found dead on the carousel only hours before her coming out.
Three cases. A murder during the Feast of San Gennaro with ties to a financial services company. A body sitting upright on a Central Park bench. An apartment fire where a 10-year-old boy died of smoke inhalation.
Mac, Stella and Flack investigate the death of a young dancer who recently won the lottery, and it isn't long before they realise that her death is connected to Lindsay's investigation concerning the death of a tram driver. Danny and Hawkes look into the murder of a local fish merchant, and soon find their way to a jealous friend who was angry that their child didn't get into a prestigious school.
When a man is found murdered in an elevator, Mac, Flack, Danny and Lindsay investigate a world where very young girls enjoy sexual encounters with much older men. They're left trying to determine whether their best lead is a suspect, a witness ... or the intended victim. Stella and Hawkes investigate the death of a young man found in Central Park who died from an extreme allergic reaction and learn that he had been pretending to be someone that he wasn't.
(Crossover episode with CSI: Miami, Season 4 Episode 7.)
Horatio Caine follows Henry Darius to New York so that he can keep his promise to a young boy in Miami, but by the time he and Mac are able to locate Darius he has disappeared again, leaving behind six more bodies. A link to the younger sister of one of the victims who was also Darius' hostage turns out to be a dead end, but Mac and Horatio soon find the connection between Darius and his hostage, leading them to a psychiatrist who had treated both.
Mac and Stella investigate a murder of a host of a high stakes poker game after a player was caught cheating and kicked out of the game. While Danny and Hawkes follow the clues that'll lead them to solve the death of a weather girl.
Danny and Stella find innovative ways to process a crime scene while Danny is trapped in a panic room with the victim, who was the only person with the security code. As a locksmith works to cut through the titanium doors, the CSIs rush to process the evidence before the victim decays further and Danny's oxygen runs out. Meanwhile, Mac, Dr. Hawkes and Lindsay investigate the murder of an exotic dancer found dead on a klieg light
Mac, Danny, and Dr. Hawkes investigate the death of a runway model who collapsed during a fashion show. Meanwhile, Stella, Detective Flack, and Lindsay investigate a teriminally ill patient's confession to the murder of his doctor.
Danny is on his way home after a long shift and finds Randy Williams subway surfing. Mac and Lindsay arrive on the scene and begin to wonder if Randy Williams died from riding on top of the subway. His death is even more suspicious after they examine the body more closely.
Stella is invited to an art gallery where she sees several paintings done by an artist named James Golden. Stella thought she was going to Frankie's place and not to an art gallery. Outside the exhibit two people are kissing and one of them is shot in the back with an arrow.
Lindsay, Stella, and Mac are on the case of a dead ADA, who they discover, is involved in a "kill war" with water guns. Meanwhile, Danny and Hawkes investigate the murder of a young lady who had a penchant for suing restaurants and taking them for all they are worth.
A young boy witnesses the death of a museum curator but doesn't want to tell anyone about it. Danny investigates the death of an urban golfer found dead on a construction site.
A man dressed in a superhero costume is found dead in an alley, after saving a man being mugged. Mac, Stella, and Dr. Hawkes find his clothes in a nearby phone booth. Danny and Lindsay investigate the murder of an NFL first-round draft pick, known as "Superman."
Mac receives a phone call confessing to an old murder before the caller commits suicide. The call leads the team to a football stadium to uncover a body and they learn the suicide victim belongs to the Tanglewood gang. They also find a cigarette that puts Danny's job on the line after his DNA is found on it.
Stella and Danny investigate the death of a businessman who used the services of an expensive call girl service.
Mac and Lindsay question Kid Rock because he was the last person to see his limo driver alive when the driver is found dead in the alley just before Kid Rock’s encore performance concert.
Two women both claim to be the wife of a murder victim surprise Mac and Stella at the circumstances of their relationships. Both women have been in a trinogamous marriage with the victim. Meanwhile, Danny and Lindsay investigate the murder of a young woman who is found off a dock tangled up in kelp while she is dressed as a mermaid.
Mack and Danny investigate a Marine found dead in Central Park during Fleet Week. The evidence doesn't add up and who is Ellie? Stella, Lindsay, and Hawkes investigate a dead body found in a burnt out car. The results of their investigation leads to a devastating loss for the whole team.
After a routine call leads two of the team into finding a bomb, they evacuate but a few are still in the building along with Mac and Flack when the bomb detonates. After the explosion the CSI's face a race against time to find the bomber and the possibility of losing one of their own. Mac must come to grips with having let a Marine die in Beirut in 1983.