Gil Grissom and Sara Sidle come to the aid of a former colleague who is implicated in tampering with evidence. Maxine and the rest of the CSI team work the murder of a couple slain on their wedding day, following the evidence to the salacious underbelly of the Las Vegas elite.

Max puts CSI on lockdown when evidence in a new murder tips Grissom and Sara to a new suspect in the crime lab. Also, Folsom and Allie investigate a series of chilling killings at a dilapidated clown-themed hotel.

The CSI team looks closely at the eccentric world of sideshows when a couple of performers are discovered burned in a pit. Also, Hodges mulls a plea deal as his criminal trial kicks off, while Max, Grissom and Sara search for evidence to exonerate him.

When David Hodges goes missing, the entire CSI team searches for any piece of evidence that can help locate him, clear his name and save the reputation of the entire crime lab.

The CSIs investigate the murder of a dominatrix found near her secret sex dungeon.

When three masked assailants invade a home and murder an entire family, including a pregnant woman, the CSIs are called to the scene to investigate. Catherine leads the team through the emotional case, which intensifies her own longing to reconnect with her estranged daughter, Lindsey.

When the bodies of two Regency Romantic Festival attendees are discovered, the CSI team uncovers a shocking link between their murders and previous cases.

When a young, non-verbal boy is found hiding in a stranger’s garage, the CSI team searches for his missing mother. Also, Max receives a strange letter with symbols in silver ink that Folsom and Allie recognize from prior crime scenes.

The CSI team investigates the death of an archaeologist found near the breakthrough discovery of an ancient civilization. Also, Max locates another cryptic note written in familiar silver ink after a mentally distressed woman kills her attacker.

A silver ink note threatening Maxine Roby's life is found at the crime lab, sending the entire CSI team to crack who is behind the notes and how they connect to other murder case.

Medical examiner Sonya's life is in jeopardy when she is exposed to a mysterious poison as the CSI team races to find the antidote and the silver ink murderer who appears to be targeting the Crime Lab. Max's ex-husband, Daniel, returns to make sure that she and their son are safe.

When the body of a young girl who was killed over 40 years ago is discovered at the bottom of Lake Mead, Max Roby promises her mother, Raquel Williams, that the CSI team will finally find justice for her daughter. Also, Greg Sanders brings his quirky humor as he returns to the crime lab.

The CSI team investigates a bomb that detonated during a masquerade party for wealthy investors at the site of a new casino.

The CSI team investigates a murder case that hits close to home for Folsom. When he is forced to sit this investigation out, he does his own digging with help from Trey. Worried Folsom will do something he regrets if he gets his hands on the killer, the team find themselves racing to arrest the suspect first.

With their respected colleague Josh Folsom under arrest for the death of Kahn Schefter – the man responsible for killing Folsom’s mother – the CSI team combs through every crumb of forensic evidence to determine his innocence or guilt.

With a new piece of evidence at play, Catherine Willows reopens an investigation from her past that never got solved after a violent attack left her hospitalized. Internal affairs begins questioning Folsom.

The CSI team is called to investigate when the bodies of Frank Sinatra and Joey Bishop impersonators are discovered behind the drywall of a home construction project. Also, Folsom must face the review board about the future of his career.

When a mechanic is found murdered in a dark factory, the CSI team investigates whether the perpetrator was human or a humanoid robot with an AI operating system.