A robbery takes place while Mac is in a convenience store. He is shot and in critical condition. The team rushes to find the shooter.

A woman claims that her husband was accidentally shot and killed in the lobby of a building, but the team soon discovers that she is hiding a lot of secrets about the crime.

The team tries to figure out who killed a Hell's Kitchen businessman and placed his body parts at the four corners that mark the neighborhood's original boundaries.

A process server is killed, and the team finds out he treats his job just like a video game of track and complete missions. The murderer is linked to competitive video games in a tournament.

When one of their own is killed, the CSIs must figure out why the murder scene is a detailed recreation of an unsolved case from 1957. Also, Mac and Christine continue to grow closer.

When the same type of chewing gum is found at two separate crime scenes involving two dead bodies, Jo operates on a hunch that the two cases may be related.

While investigating a murder, the team discovers that the son of a hedge fund billionaire has been kidnapped.

A real estate mogul is killed in a home invasion, but was somebody close to him ultimately responsible for his death?

The team suspects that a badly burned corpse may be of a cage fighter, but later discovers that he may have faked his own death.

The ability to find justice for John Curtis is put in jeopardy when he is freed on bail, the accuser is killed, and the team uncovers a possible conspiracy to frame him.

The team tries to identify the shooter and motive in the assassination of a criminal court judge presiding over the trial of a Russian mobster, while Mac and Lindsay prepare for the hearing against serial rapist John Curtis.

A dead body is found in the remains of a collapsed porch from a high school party, and the team discovers that she was strangled before the accident. Meanwhile, a serial rapist from one of Jo's past cases strikes in New York City.

A fraternity pledge master is found dead in an open grave, and the team soon suspects that one of his pledges may be buried alive in another cemetery in New York City.

When a young woman is stabbed to death, the junkie brother of a high school basketball phenom is accused.

One of Danny's rookie officers claims that she shot an armed man who attacked Danny outside of a barroom. However, the gun is not at the scene, and is used in a later shooting.

The dead body of a high end car thief is found in the trunk of a car she stole, and her family may be in danger.

The boyfriend of a punk rock singer is shot to death in his apartment, and the key to solving the crime may be his missing roommate.

On the 10th anniversary of 9/11, Mac and the team remember specific moments from that day that were indelibly burned in their mind.