Horatio investigates the death of a man who accidentally inhaled a lethal combination of chemicals in a neighboring house after he went inside to retrieve his cat. Elsewhere, a resident of a retirement community is found dead in a pool of blood, an apparent victim of a vicious attack.

Horatio hunts for the person responsible for a vicious attack on a woman who was lured to a vacant condo and beaten with a piece of lumber.

A young woman is thrown over the railing of a parking garage, but the investigation into her death uncovers evidence that she was killed before the fall and had likely been kidnapped. The victim's watch is traced to her boyfriend, who tells the detectives that she was a thrill seeker who was abducted during the course of an extreme kind of role-playing game. Meanwhile, Delko gets into trouble when he inadvertently interferes with a case after stumbling across a car-theft ring.

A celebrity photographer is found dead in his car following an accident, but Horatio believes he was murdered. The investigation leads to an A-list movie star who was caught in a compromising position in photos taken by the paparazzi.

Horatio and Speedle's case hinges on the testimony of a forensic-evidence enthusiast who stole a blood-drenched latex glove from the scene of the murder of a man who was stabbed to death with a butterfly knife. When Speedle tracks him down, the CSI wannabe is impressed by the ease with which Speedle was able to locate him, and the two begin to develop a slight bond when he shows up at the crime lab the night before he is set to testify. However, their relationship is cut short when the young man is found dead in his forensics-shrine of a home. Meanwhile, Delko and Calleigh probe the shooting death of a young woman whose body is found wrapped in a plastic garbage bag in a dumpster near the ritzy Miami club where she worked.

After a large yacht slams into a major Miami bridge, the team finds that the man steering the boat was shot and killed before the accident. The victim's wife reveals that their son had been kidnapped and her husband was handing over the ransom – three million dollars worth of jewels. But when the team learns that the jewels were fake, the investigation leads them into a dangerous situation at a jewelry shop that may contain crucial evidence, where Horatio must face the unimaginable when one of the team is killed in the line of duty.

As a huge tsunami heads directly towards Miami, a ten-hour warning gives citizens just enough time to evacuate the city. In the chaos, two people are killed in a parking lot and the evidence leads Horatio to discover a plot to rob a bank timed to take advantage of the evacuation. However, as the CSIs close in on the robbery already in progress, they find that it's a more elaborate crime than they previously thought. In the wake of the storm, Ryan and Alexx discover a body washed up from a local cemetery that may have a different cause of death than originally recorded. Meanwhile, Horatio suspects that Yelina is being physically abused by her boyfriend, IAB's Rick Stetler.

Evidence leads the CSIs to believe that someone started a massive fire in the Everglades in order to cover up a murder. Local prisoners are brought in as free manpower to help fight the wild fire in the Everglades. However, when a serial killer escapes the scene, Horatio must track him down before he strikes again. Meanwhile, the body of a local college student is found shot to death and the fire has destroyed the crime scene and the evidence. However, when the team uncovers an illegal moonshine operation and homemade ammunitions in the vicinity, the CSIs uncover the real reason why the boy was out there.

Horatio's life is changed forever when he learns important information about his deceased brother. Horatio must now figure out what to do with this information about his brother, Raymond, and whether or not to tell Yelina. Meanwhile, the team investigates when a woman is murdered at a crowded bar after she's approached by a female employee of a service that helps men pick-up women. Also, when Delko loses his badge after some reckless behavior and it's used in a crime, he must locate the badge before it's used again.

An axe murderer on death row is given a stay of execution just moments before it was to take place, on the grounds that there may have been tainted DNA analysis used at his trial. Now, without using any DNA evidence, the team must race against time and reexamine all of the physical evidence in the case, just as they get a call on a new double murder that looks suspiciously like the case they're working on.

While investigating the murder of man hired to make dirty bombs that terrorists intend to set off in Miami, Horatio finds the bloody fingerprint of his brother, Raymond, who he believed to be dead. However, when Raymond's son is kidnapped, he emerges from deep undercover and the estranged brothers must work together to save the boy. Meanwhile, while processing a crime scene, an unknown assailant holds a gun to Calleigh's head and, after a deadly confrontation in her gun lab, she is left doubting that she can continue as a CSI.

The team must find the connection between the two crime scenes; the killing of a drug dealer and the rape of a well-off family member.

(Crossover episode with CSI: New York, Season 2 Episode 7.)

A crossover episode that concludes on "CSI NY" begins with a convicted serial killer who escapes after sabotaging an airplane that was flying him from New York to Miami, where he allegedly buried a body. After fleeing the crash site, the man goes on a killing spree and abducts a college student. Mac Tayor arrives to help Horatio track the killer since Mac originally arrested the man in New York.

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 in this 100th episode of CSI: Miami.

After a young woman is found dead shortly after she was auctioned off for charity, the team finds that the woman was trying to uncover the true nature of the event’s host. As the team delves deeper into the investigation they soon discover a larger plot that could put Miami in danger.

The murder investigation of a sports legend has complications when his body is lost by the lab.