Horatio and Delko arrive in Rio de Janeiro to avenge Marisol's death. They go on sniffing after the trail of Antonio Riaz, who ordered the hit on Marisol.
Calleigh gets run off the road with freshly collected evidence in her car. The evidence gets corrupted, leaving the team in a tricky situation. They must try and collect new evidence that is usuable, but most of it is water-damaged.
The dead body of a celebrity is found at an A-list party. They soon discover that the murder is linked to a “death pool,” where gambling occurs on an offshore ship. A counterfeit ring is also discovered where 100-dollar bills are produced.
When a male model is murdered, the CSI team's investigation leads them into the world of modeling as they search for the killer.
A local politician who was supporting the eminent domain that would force a neighborhood of people out of their homes is murdered. To complicate matters, Horatio finds out that the judge hearing the case is dirty.
A Santeria follower is found murdered and strange things start happening around the lab leading the team to believe there is a curse. But their focus changes when they discover stolen gold is involved.
A deadly crash occurs at a sideshow and the team investigates. They discover the crash was caused by a remote signal sent by a cell phone and track that back to one of the financiers of the show who staged the crash for a publicity stunt.
Natalia's sister is a missing girl in one of the team's cases. They track her to an amateur photographer who has been snatching and killing women who come to model.
A young woman who is auctioned off at a charity ends up murdered and as the team investigates they discover that the host of the charity event is actually a drug dealer. However, as they continue to investigate the team realizes that the case is much bigger than a drug dealer and a murder victim.
The team investigates the murder of an army recruiter as well as an enlistee that was killed in an attack.
Sonya Barak is standing trial for aiding in a plot to destroy Miami when her own people try to gun her down, suspecting that she may be a traitor and in cahoots with the police. When she goes on the run to stay alive, Horatio, never wavering in his belief that she is innocent until proven guilty, must find Sonya before they kill her once and for all.
Natalia's ex-husband Nick is killed and Natalia is the prime suspect. Horatio and Calleigh's cop ex-boyfriend must find evidence to prove Natalia innocent as most of the team sits this one out to avoid trouble from Internal Affairs.
While investigating a crime scene, Tripp steps on a land mine and Horatio and the bomb squad must deactivate it. Delko faces a $250,000 law suit from a domestic dispute he handled.
Horatio's old enemy, Clavo Cruz returns putting the lives of two CSIs in danger. On the day of Clavo's arraignment a missile is launched into the courthouse so he can escape. When Eric is shot, Horatio is more determined than ever to put Clavo away for good.
Eric is revived after being pronounced dead. The team takes turns checking in on him while they try to catch his killer, Clavo. When he wakes up, it appears that there may be some brain damage.
A babysitter gets a scare when she discovers her father's body while babysitting at the neighbor's house. The investigation leads them to discover some burglaries and then Horatio uncovers evidence that points at a doctor with secrets.
A group of men go hunting, but one of the group dies in a bear attack. The team discovers that the men were set up as bait and the death may have been set up to cover up the murder of a high class call girl and her bodyguard. The investigation leads the team to an illegal prostitution business catering to some important people in Miami.
A real estate developer is killed at a charity event, and the main suspects are his wife and her two secret twin sisters.
When Horatio and his team investigate a murder where the victim is found scalped, they must investigate the owners of a nearby Native American Casino.
A movie star's body is found in the trunk of a car while the staff is shooting a car scene. Horatio and the team must investigate his death to determine who killed him and learn that he was in a celebrity rehab center and about to expose some damaging secrets.
A nasty divorce gets even worse when the husband's mistress turns up dead. As the body count increases, the soon-to-be ex-couple's relationship turns out to be even more complicated.
A man is killed in a fire in his home, but his girlfriend escapes. Meanwhile, Horatio must fire Ryan when he doesn't disclose that he knew one of the suspects. But as they investigate the team discovers that the man and his girlfriend actually set the fire, planning to frame the woman's ex-boyfriend. The plan backfires when the fire goes off and the man is killed.
After a suspected carjacker is murdered, the CSIs learn that the victim may have been involved in drug smuggling off the shores of Miami with a very dangerous drug lord.
When a serial killer suspected of killing young women and branding them with a 'Y' is caught and identified as having the extra Y chromosome, the 'criminal gene,' the team feels that they have closed their case. Unfortunately, another killing happens while the killer is in custody. The team catches the second killer and unravels the mystery that started the killings.