A very skilled and famous skyscraper climber falls off the Empire State Building while attempting to scale it. Mac Taylor and Sheldon Hawks (on his first field assignment) investigate the case. In another part of the city, Stella Bonasera and Danny Messer must solve the mysterious death of a famous designer found dead, wearing his latest creation which is a bra made of diamonds. Aiden Burn works solo on a rape case.
A plastic surgeon is found dead at Grand Central Station during rush hour. He apparently died from inhaling lye. Stella and Danny investigate the death of a blind woman. Aiden is more intent than ever to solve the rape case that she does the unthinkable, an action which forces Mac to fire her.
Detective Lindsay Monroe joins the CSI team. Her first case leads her to New York's zoo, where a dead man has been found in a tiger's cage. However, it is soon stated that the man wasn't killed by the tiger, but by another person.
Detective Taylor and Lindsey Monroe delve into a murder during the Feast of San Gennaro with ties to an oil company. Detective Flack and Hawkes investigate a mysterious case of arson where a 10 year old boy dead of smoke inhalation.
A young girl lands on the windshield of the car. Her feet tells Stella that she was a dancer. Lindsay Monroe works solo on the death of an old tram driver. She soon realizes that her case is related to the first. The third case involves the death of a fish merchant. He died from a fatal wound caused by a swordfish.
A young woman gets on an elevator with an older man. When the door opens on his penthouse, he is shot by an unseen person. The girl is not hurt and the team must track her down as she is the only eye-witness of the murder. Stella and Sheldon Hawks fish a body out of a pond in Central Park. The man, however, did not die from drowning. He suffered a fatal allergic reaction.
Four men are playing poker in an apartment. When they catch a man cheating, the other men throw him out. Just a few moments later, the doorbell rings; when one of the players looks through the peephole, expecting to see the recently departed cheater, he is facing the barrel of a shotgun and is instantly killed. Meanwhile, in Central Park, a TV weather girl is found dead on the ground. Autopsy reveals that she drowned, even though there is no water near the crime scene.
A teenage boy stumbles upon a dead body in a shop full of dolls. The man was the owner of the doll hospital. The room shows signs of a great struggle with dolls scattered all over the floor. In an upscale apartment, Stella and Sheldon Hawks examine the body of a waitress who had cancer. As oppose to the other crime scene, this room is in perfect order except for a spilled can of soup.
A female roller derby dies during a game. At first glance, it seems that she was trampled to death. However, autopsy reveals that she died from heating up from the inside. The other case involves the death of a writer found in a dumpster and wrapped in an expensive rug.
Danny and Stella are investigating a murder of a billionaire in a crime scene what seems to be a bedroom but while Stella is interrogating suspects, Danny searches the room for possible evidences and Danny manage to push a button that turns the bedroom into a panic room. With Danny trapped inside the room, they have to find a way out for Danny while a murderer is at large.
A famous model drops dead on the catwalk. Though she is thin, the young model is very healthy. Mac, Danny, and Sheldon Hawks work together to solve the mystery. At the PD, a man gives himself up and confesses that he has just killed his doctor. However, Stella does not think he is the murderer as he cannot give her specific details of the crime.
On a trip home from work on the subway, Danny sees a body laying on the tracks. Luckily, he manages to stop the train before destroying any evidence. Mac Taylor, arriving from a Mayor's reception in his tuxedo, and Lindsay Monroe join him. Stella and Hawks investigate the death of stock broker found hanging from a noose off of the window of his fancy office. As usual, the hanging was staged as the man was strangled to death.
Danny and Lindsey investigate the death of a music promoter and enter the world of ad posting wars between up-and-coming bands. A billionaire playboy is found impaled on a billboard with a model after throwing a party for an artist.
A man is found dead in a cemetery. The wound on his chest indicates that he died from a bullet wound, yet the CSIs found nothing but small pieces of paper inside it. The second case is of a dead woman found blindfolded with her hands tied behind her back in her fancy bed. The investigation leads the detectives to a restaurant that serves exotic food such as centipedes, live octopus, and cockroaches.
A doorwoman is found dead in the water tank of her apartment. All the evidence which are readily available points to a doctor who lives in the building. However, the man swears that he had nothing to do with the dead woman. The other case is of a man found dead on a playground in Washington Heights.
The body of a woman, half eaten by beetles, is found in a museum exhibit. The only eye-witness is a young boy who refuses to talk. Danny works solo on the case of a dead urban golfer found dead on a construction site.
A man dressed as a superhero, complete with tights and a cape, is found dead. The investigator finds that he is a patient living a home for the mentally ill. As they dig deeper, they find that someone working there is illegally selling prescription drugs. The second case is off an up-and-coming football player found dead inside his hotel room. The very healthy athlete died from a small puncture wound.
A limousine driver is shot dead inside his car, while a concert by Kid Rock is happening inside. Lindsay and Danny works on the case. Mac hears of a shooting on the police radio at Stella's address. He rushes to the scene where Stella is on the ground unconscious, while her boyfriend, Frankie, is found dead. Gunshot residue confirms that she shot him.
The CSIs arrive to investigate the death of a man shot in front of his house. A woman runs towards the scene crying that the decease was her husband. Moments later, another woman also claims that she is the dead man's wife. It turns out that the three people were a committed threesome. The other case starts with the discovery of a woman dressed as a mermaid found inside the river.
The US Marines are staging a small show in Central Park. During one of their games, a young boy finds the body of a noncommissioned officer. The Marine was highly decorated having served in many campaigns. The absence of any defensive wounds is puzzling to Mac Taylor as the victim was a very strong, well trained and combat hardened Marine. The second case involves a burnt body inside a car. Facial reconstruction reveals a shocking answer. The victim a familiar face.