As the fourth season begins the team find themselves investigating something that isn't usually on the Statue of Liberty. Can a musician's life be saved before time runs out?
After a series of heists in the city (one including Det. Chief Sinclair's house) one of the "super spies" involved is robbed of his life. The team works to solve the robberies and the murder, as both are obviously connected.
The latest murder case takes Detective Taylor to a whole new world and he must figure out why Cheryl Duncan looks so life-like. They also discover something shocking about the murderer while online.
The CSI team goes to a haunted house to solve more than just the latest case. Before they can solve the crime Lindsay is told something will happen to her if she doesn't leave soon.
The team has two cases tonight and two great tourist locations: Madison Square Park where a man is stabbed to death, and the Metropolitan Museum of Art, where a woman is shot dead on the steps.
What is even more perplexing about these cases is that the team soon realizes that these two victims hold something criminal in common.
New York City has everything: Times Square, billboards, parties, and a dead model in a giant martini glass. Now the team must find a party crasher who crashed one party too many.
What would otherwise be a happy wedding goes sour when the groom... turns up dead: inside a wedding present. After Stella finds bloody puzzle pieces inside a box on her car, Mac heads home to Chicago to solve what could be the murkiest mystery of his life.
While in Chicago Mac uncovers more clues about his stalker and reveals his troubled past. Meanwhile, in New York the rest of the team is in danger. The hunt is on to figure out the identity of the 333 stalker before time runs out.
Danny is devastated when a young boy he knows is killed in the midst of a bodega robbery. Meanwhile, Lindsay, Stella and Flack investigate the death of a man killed by an exploding cigar that is connected to a joke shop proprietor and another tragedy that occurred years before.
Mac and the team feel they're headed back to Kansas when they find the victim's body with red shoes on her feet crushed to death under an unusual object. The team learns about pop up parties after finding a body.
In this episode Mac and his team must figure out how a woman's death and a judge's murder are connected. Danny has trouble dealing with Ruben Sandoval's death.
The team must figure out how a self-cleaning restroom leads to a drowning.
The team also investigates the death of a man who was set on fire and flew into a fire truck.
Stella's life is in danger after her apartment is on fire; she must try to save everyone in the building. The team also has a mystery to solve after finding a dead body in Stella's apartment building.
The team must figure out how a young woman and a shark end up dead on the beach at the same time. This case gets even more interesting when a second body washes up on the beach.
Quinn Shelby observes the team at work to determine if the lab should get their annual accreditation.
When a guidance counselor is murdered at a private school, the mayor orders Mac and his team to drop everything to find out what happened. Mac is frustrated because he can't devote the man hours or the personnel to finding the "Taxi Cab Killer".
As the search for the taxi cab killer continues riding a cab gets very deadly. The team must figure out how to keep New York City safe.
Also Danny, Lindsey, and Flack investigate the murder of a man who made a half court shot during a game that both Danny and Flack were attending.
Mac and his team finally believe they have captured the taxi cab killer but there is one problem - he is found dead. Mac must figure out how to keep the streets of New York City safe while continuing to track the elusive taxicab killer
When a man takes hostages during a failed attempt to rob a bank, Mac offers himself in exchange for a hostage. Only condition is that he must prove that the bank robber did not kill the bank manager, whose body is found lying in a pool of blood in the vault. On the outside of the bank, the rest of the team works to process the evidence that Mac finds and stop the SWAT team from making matters worse.