|| 901 | For Warrick|
The ninth season begins with the discovery of CSI Warrick Brown slumped over in his car after hearing the gunshots. The entire team grieves for their fallen friend while unknown to them the killer, the Undersheriff, investigates the murder. Also an old friend returns when they hear the news.
|| 902 | The Happy Place|
Nick and Catherine investigate why a woman who was about to be married would have taken a swan dive off of her balcony. Also Grissom investigates the brutal murder of a woman found in an alley. The investigation gets tougher with the discovery that her two-year-old was with her when she was murdered.
|| 903 | Art Imitates Life|
The team investigates a series of murders where bodies are posed. An artist becomes one of the suspects when they find out he has his models pose as dead bodies for his pictures. Also, being two CSI's short, Ecklie hires a new CSI - Riley Adams - and a counselor comes in to help everyone deal with Warrick's death.
|| 904 | Let it Bleed|
Nick and Riley witness a man in a police costume rob a convenience store. They then must help the rest of the team investigate the death of a young woman who turns out to be the daughter of a big time drug lord wanted by FBI, CIA, and DEA. They discover with security camera footage that she was thrown out of a club by two bouncers earlier that night. When Catherine and Riley go to the club Catherine discovers her daughter Lindsey there with a fake ID
|| 905 | Leave out all the Rest|
When the CSI team investigates a case involving the world of domination, Grissom pays a visit to Lady Heather to help find some answers.
|| 906 | Say Uncle|
The CSI team investigates a shooting at a Koreatown neighborhood party, in which the mother and uncle of a small boy, Park Bang, are murdered.
|| 907 | Woulda, Coulda, Shoulda|
The CSI teams investigates the death of a woman, married to a man who committed murder twelve years ago. In the meantime, the fate of Natalie Davis is being decided.
|| 908 | Young Man with a Horn|
The CSIs discover a link between the death of a popular young singer and a murder that happened over 50 years ago.
|| 909 | 19 Down|
When a new murder leads to a connection with an infamous serial killer, Grissom secretly joins the class of well-known criminal pathologist Dr. Raymond Langston, to gain access to the killer and get a crack in the case.
|| 910 | One to Go|
The CSI team works to close Grissom's last open case, the "Dick & Jane" murders, as Grissom prepares to leave the team for good. Before leaving, Grissom offers Dr. Raymond Langston, who helped the CSI's with the "Dick & Jane" case, a permanent position as part of the CSI team.
|| 911 | The Grave Shift|
Dr. Langston's first day as a CSI is anything but easy when a seemingly simple burglary case ends up overlapping with an in-depth homicide and arson case.
|| 912 | Disarmed and Dangerous|
The CSIs are called in when an undercover FBI agent is found brutally murdered. The CSIs must help the victim's partner find the killer.
|| 913 | Deep Fried and Minty Fresh|
Langston and Nick are called to investigate a murder at a fast food restaurant and have quite a task ahead of them when they discover that much of the evidence is coated in cooking oil.
|| 914 | Miscarriage of Justice|
While Langston testifies in the trial of a respected Congressman, new evidence sends the CSIs back to the lab to reopen the investigation.
|| 915 | Kill Me If You Can|
The CSIs are called to three different crime scenes in one night that are seemingly unrelated, but each case's forensic evidence reveals a common link.
|| 916 | Turn, Turn Turn|
We follow the happenings of a seedy motel's inhabitants over the course of a year. The CSIs are called to a few too many cases to be coincidence and one CSI in particular finds himself becoming emotionally involved.
|| 917 | No Way Out|
Langston and Riley are taken hostage during the aftermath of a shootout in an usually calm Las Vegas community.
|| 918 | Mascara|
A murder takes place in the world of Mexican wrestling (Lucha Libre) and our CSIs must solve the crime.
|| 920 | A Space Oddity|
When the "star" of ASTRO QUEST REDUX is found murdered at a science fiction convention, assorted freaks and geeks are obliged to boldly go under the scrutiny of the CSI team.
|| 922 | The Gone Dead Train|
|A series of indeterminate deaths test the deductive powers of the CSI team, who fear that a public health emergency may be in the offing. Meanwhile, a friendly rivalry over who will win an upcoming bikini contest takes a deadly turn.|
|| 923 | Hog Heaven|
|A band of vicious bikers is given the go-ahead to take down one of their own when it's discovered that the guy is an undercover cop...|