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.

Seconda parte del Crossover con CSI: Miami

Mac torna a New York con Horatio Caine, capo della scientifica di Miami, per seguire il serial killer Henry Darius fino a New York.

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.

Mac, Danny and Lindsay investigate the death of owner of a doll hospital. Stella and Hawkes look into the death of a woman with terminal cancer.

Mac and Stella work on the case of a female roller derby player. Danny and Hawkes look into the murder of one of New York's upcoming crop of writers.

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.

After the body of a dead woman is found in a water tower the team suddenly realizes that the building may hold a bigger mystery than they expected.

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.

The life of a transplant patient hangs in the balance as the team tries to find the hijacked plane carrying the liver.

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, Monroe e Hawkes indagano sull'omicidio di un giovane, e scoprono che l'omicidio è collegato al leader della banda Tanglewood Boys. Nel frattempo Bonasera e Messer indagano sull'omicidio di un banchiere, ma scopre che è collegato al caso che indaga Mac e gli altri sull'omicidio del ragazzo.

Mac e Monroe sono costretti ad interrogare una rock star Kid Rock quando, nel corso di un'indagine, si scopre che l'uomo è l'ultima persona ad aver visto vivo l'autista della sua limousine. Nel frattempo, Bonasera viene aggredita e tenuta prigioniera nel suo appartamento.

Due donne sostengono di essere entrambe la moglie di un uomo che è appena stato ucciso, il caso è occupato da Mac, Bonasera e Hawkes. Nel frattempo, Messer e Monroe indagano sulla morte di una giovane donna, ritrovata vestita da sirena nelle acque del porto.

Mac e Messer indagano sull'omicidio di un caporale dei marines, ma alcuni particolari inerenti alla morte dell'uomo sono piuttosto oscuri. Bonasera, Monroe e Hawkes indagano sulla morte di un cadavere carbonizzato in una macchina, ma Sid scopre che il corpo è quello di una donna.

Mac affronta il suo passato ed in particolar modo, nel 1983, lasciò morire un compagno marine a Beirut. Nel frattempo, la squadra cerca di prevedere la prossima mossa di un folle dinamitardo.