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.

E-mails and text messages trigger a mass gathering of students to perform a random task on a golf course. However, as the crowd disperses, the body of a high school student is found. The original message triggering the "flash mob" is traced to a high school senior whose father is a high-powered defense attorney. The case changes direction when Horatio and the team learn that the schoolmaster's daughter may have had something to do with the murder and evidence reveals that the victim was having an affair with his chemistry teacher.

An 18-year-old girl is stabbed to death in a bathroom of a popular Miami nightclub. Horatio learns that the victim was an investigative aide working for Alcohol Beverage Control and was monitoring underage drinking. As Horatio interviews the club's owner, an unknown man drives by the club, sees that the police are there, and crashes his car while fleeing the scene. However, the case gets more complicated when they discover another murdered victim inside the car. DNA from the second victim's watch ultimately leads them to a day spa where the services may not be entirely legal. Meanwhile, Calleigh and Ryan work together to determine whether an insecure and underage teenager at the club that night had anything to do with the murder.

A murder investigation takes Horatio and the team into the world of speed dating. Richard Laken is found killed by a tire iron outside a lounge following an evening of speed-dating. The team discovers his car is covered with acetone, which traces back to one of the female guests. She reveals that she dated Laken and he dumped her, so she doused his car with nail polish remover for revenge, but she didn't kill him. Now, when Horatio and the team learn that Laken recently witnessed a serious assault at a Miami Heat basketball game, they are on the hunt for two perps instead of one.

Als sechs tote Seeleute von einem tauchenden Pärchen entdeckt werden, deutet alles auf einen Akt der Piraterie hin. Doch offenbar haben die Piraten nicht alle Besatzungsmitglieder des betroffenen Schiffs getötet.

Ein Fußgänger kommt auf bizarre Art und Weise ums Leben: Er wird von einem aus einem Gebäude herabstürzendem Mann getroffen. Bei den Ermittlungen stellt sich heraus, dass der Vorfall offenbar kein Unfall war.

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.

Bei einer routinemäßigen Verkehrskontrolle wird ein Polizist erschossen. Ein Praktikant, der ihn bei der Kontrolle begleitet hat, ist verschwunden. Die Ermittlungen des CSI-Team führen zu der Schülerin Missy Marshall, die den Beamten auch gleich einen Verdächtigen präsentiert. Doch das Mädchen scheint mehr zu wissen, als sie zugibt...

Nach einem Großbrand in den Everglades gehen die Ermittler davon aus, dass es sich um Brandstiftung handelt, die von einem anderen Verbrechen ablenken sollte. Dann wird die Leiche des Studenten Paul Travers gefunden. Er wurde erschossen...