Megan Donner returns to the CSI unit in time to work on a jet crash in the Everglades. While searching for survivors, they inexplicably discover a female victim found five miles from the crash site. When the only survivor says the woman opened the plane's hatch in order to commit suicide, Horatio is suspicious. The team must now recreate what happened on that fatal flight, especially when the pieces don't quite fit together.

A serial bomber is on the loose. Will the team with the help from Caine's old bomb squad mentor be able to work out the puzzle and find the bomber?

Horatio, Calleigh and Speedle investigate the death of an exotic male dancer found dead after a sexual party, and must dig through the evidence to discover a motive. Meanwhile, Eric and Megan investigate the death of a man involved in diving that mysteriously died after climbing onto a random boat.

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.

The CSIs must find the killer after a young woman is pushed in front of a moving bus. Alexx finds a bruise shaped like a hand imprint on the victim's back, proving that she was pushed in front of the bus, and her boyfriend, Jay Seaver, is the prime suspect. When one of Jay's office rivals also turns up dead, Jay reveals that he has a psychotic stalker, Claudia, who he thinks might kill to please him. However, when Jay hires a lawyer to protect Claudia, Horatio suspects that Jay may be more involved than they thought. Later, a man's body is discovered down an elevator shaft in a nearby building, and there is evidence to link the victims to a common killer. Meanwhile, Calleigh's father seeks her help when he fears that he may have killed someone after a night of drinking, and Horatio assigns a new CSI, Ryan Wolfe, to the case.

The wife of a famous baseball player is brutally killed in her home and her philandering husband is charged with the crime. The jury on the case, as well as the accused and his defense, visits the house to examine the crime scene, but when the lights are dimmed, as they were when the victim was killed, and then turned back on, the ball player is found dead with a meat clever in his back and a note that reads "guilty." Now, as Horatio and the team find that the husband's defense team tampered with the crime scene, they must examine the evidence to find the couple's killers. Meanwhile, Horatio gets a call from Yelina, who tells him that her son, Ray, Jr., is missing.

The team investigates a modern-day piracy off the coast of Miami after six bodies are discovered floating in the ocean tied together by rope. Horatio suspects that a ship was hijacked with some of the crew killed and then dumped overboard. Evidence suggests that other crew members might have escaped on a life raft. Using radar and GPS technology, the CSIs find survivors but their stories don't match. Now, Horatio and the team must learn what really happened out in the ocean as they find themselves investigating the seamy underbelly of Miami's militias and arms dealers.

When gang-related gunplay goes down in an emergency room, Horatio and the team must find the gang members responsible. The evidence suggests that an orderly in the hospital recognized the wounded gang member, who possibly killed one of the orderly's friends and alerted gang members to his location. However, the evidence doesn't match up and the CSIs discover that a cheating girlfriend, not gang retaliation, may be behind the shooting. Meanwhile, Ryan questions a mother in the emergency room after her story regarding her child doesn't add up.

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.

An extreme skateboarder and videogame tester is found dead on a half-pipe platform used to program extreme skateboarding video games. The CSIs discover that he was wearing reflective sensors when he was killed, so the motion-capture device used to produce these videogames recorded the murder as it happened, but not the murderer. Now the team delves into the highly competitive world of videogame programmers and testers to find the killer.

After a bitter custody battle, shots are fired outside the courthouse. Bullets fly and the target is the little girl's mother. Horatio goes after the father, who he suspects may not be the girl's biological father after all. However, when the mother's shady past is uncovered, the team finds that she has a lot of enemies who would like to take a shot at her. Meanwhile, Calleigh's father returns to the crime lab for her guidance but for an unexpected reason.