An expert climber scales the Empire State Building and witnesses a murder on the 34th floor before falling to his death. Mac and Hawkes, who recently transferred to the field, work the case. The murder victim is the head of a prestigious law firm located in the building. Across town, Stella investigates the death of a man found wearing a diamond-studded bra worth millions, and Aiden tracks a rapist who attacked the same woman twice.

A renowned plastic surgeon is killed in Grand Central Station when lye is splashed in his face and on his hands, during the morning rush hour. Mac soon learns that suspects abound since some patients had filed malpractice lawsuits against the doctor. In another case, Stella probes the murder of a blind woman on a Manhattan rooftop. The investigation leads Stella into the world of cuddle parties. Also: Aiden tries to find evidence to send a repeat rapist to prison.

Mac and Danny question the employees of a meatpacking plant after the owner was mauled and eaten by a tiger at a New York animal conservatory. Meanwhile, Stella and Dr. Hawkes probe the murder of a debutante who was found dead on a carousel in Central Park.

Mac investigates when a businessman is decapitated by an unknown weapon while sitting on a bench in Central Park. In lower Manhattan, Stella probes the apparent beating death of a man who was allegedly trying to steal money at the San Gennaro festival. And, after a 10-year-old boy is killed in an apartment fire, Hawkes examines the evidence and quickly rules it arson.

A wealthy businessman dies after being blasted with a homemade shotgun in his apartment-house elevator just as the doors opened onto his penthouse floor. The victim's young female companion witnesses the shooting, but escapes. In Central Park, a man's body is found weighed down and submerged in a lake. The investigation reveals the man didn't drown and that he was dead before he hit the water.

A woman falls from the Queensborough Bridge and crashes through a car's windshield. The investigation reveals that she was a dancer with at least one rival at a local dance company. In a South Bronx fish market, a man is murdered with a swordfish. Also: a Roosevelt Island tram operator just days away from retirement is found dead inside the tram.

A crossover episode that began on "CSI: Miami" concludes with escaped serial killer Henry Darius murdering a group of teens in a luxury apartment where he tries to steal millions of dollars from a high-tech security vault. While working the case in Manhattan, Horatio is served with a subpoena that names him as a suspect in an unsolved murder more than 20 years ago in Queens. Darius: James Badge Dale. Sarah: Kat Dennings. Feldstein: Rick Hoffman.

A poker player is gunned down in his apartment after a fellow player was caught cheating and thrown out, and then allegedly returned with a shotgun and blasted the victim through the front door. In Central Park, a woman who worked as a weather reporter at a local station is found dead and the evidence indicates that she drowned, even though her body was not found near any water. The investigation reveals that the woman's death may be linked to a sex tape she made with her boss.

The owner of a doll hospital is found dead in his place of business clutching a doll that holds the key to his murder. The investigation reveals that the victim recently filed a complaint against a delivery company and had argued with a delivery person. Across town, a young waitress is discovered dead in her bed. Stella soon learns that the woman had cancer and only had three months left to live.

An up-and-coming star on a women's roller-derby team is killed during a game when a fight breaks out and she's attacked by members of the opposing team. Across town in a park, a man's body is discovered rolled up in an expensive Persian rug that is found inside of a dumpster. The investigation reveals that the victim was a struggling author and that someone wrote passages from a book all over his body.