After a skeleton is found on a tour bus and turns out to be over a decade old, Mac and the team use the backpack they have found to track the belongings to a young man named Aaron Moreland, only to learn that the body they have cannot possibly belong to him. By tracing the victim's shirt, detectives are led to a youth center worker who claims not to remember the boy, but is hiding an old secret of his own.

Two cases. One involves multiple homicides at a restaurant and the other starts with an amputated leg found in a dumpster.

When the body of a young woman is discovered at a laundry facility, the bed sheets she is wrapped in lead Mac and Stella back to an upscale New York hotel that houses diplomats from around the world when the United Nations is in special session. Meanwhile, Danny and Aiden investigate the death of a homeless man found dressed as a human statue. By all accounts, the prank is deemed a misdemeanor, but Danny decides to delve further and his refusal to stop the investigation puts him at odds with Mac.

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.

(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.

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

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.

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.

The body of a man is discovered on the Brooklyn Bridge, and the only evidence is a huge marriage proposal in lights. The CSI team works through the investigation as they learn to deal with a new medical examiner.

The next case for the CSI’s gets even tougher when a paintball player turns out to be the prime suspect and later goes missing the team also has another problem the evidence that should point to the prime suspect points to someone else.

The CSI team has a problem after learning the family is deaf: now they have to find a new way to catch the killer. Meanwhile, more information is given on Lindsey's horrifying past and what led her to become a CSI.

Reed Garret gives Mac some interesting information regarding the death of a college student. Also the rest of the team will need to be a step ahead of Ava Brandt to figure out why a security guard was murdered.

Illusionist Luke Blade may have to defend the art of magic after an illusion is thought to have killed two people.

Back in Montana Lindsay will need to take herself back to the time when she was fourteen to help her remember the crime that killed four friends in order to help convict of the person that killed them.

Can the team clear a tennis legend of murder? Also Mac believes that the continuing investigation into what happened with Clay Dobson is nothing but media pressure. Can friends and colleagues help save Mac Taylor’s career before it’s too late?

Is it possible to solve a murder 24 hours before it happens? Mac wonders if the suspect traveled through time to know about the murder in advance.

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.

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.

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.

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".

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.

The CSI team investigates the shooting death of an archaeologist whose secret life may have caught up to him.

The CSIs must piece together a human jigsaw puzzle when a beloved wrestling coach's severed body parts are found buried throughout the city. Meanwhile, Detective Flack is in the hot seat when a teenage suspect dies in his custody.

When the wife of a former medical examiner is found murdered, a white powder found at the scene provides the CSIs with a major lead in tracking the killer when it is discovered that the powder is heroin made from human bodies.

When transferring Robert Dunbrook's son from prison to court, the NYPD is ambushed by a group of professional kidnappers who kill a member of the team and one of the CSI's lives hangs in the balance.