The CSI's must catch a madman causing havoc all over Miami and the team has to mourn one of their own.

Horatio og hans team jager en galning, der skaber kaos overalt i Miami, men CSI-holdet må samtidig sørge over tabet af en af deres egne. Det sker da en mistænkt angriber laboratoriet med giftgas, hvilket kræver et dødsoffer.

En ung pige, der er medarbejder på en eksklusiv natklub, bliver fundet død i en lavvandet pool. Den hovedmistænkte er en stjerne-footballspiller fra et college, som står over for at indlede en professionel karriere. Efterforskningen viser at sportsstjernen tilbragte natten sammen med pigen, og at hun var død inden hun blev smidt i vandet.

When the man who killed Horatio's wife breaks out of prison and goes on a rampage, the team tries to determine what he is after.

Memmo Fierro, som dræbte Horatios kone for fem år siden, flygter fra fængslet og begår en række mord, mens han forsøger at finde frem til sin datter, som er blevet anbragt hos en plejefamilie. Efterforskningen viser, at drabene måske har forbindelse til pigens skæbne.

En synsk mand påstår, at han har set et mord, vel at mærke før det fandt sted. Da manden senere kan udpege de steder, hvor det parterede lig er blevet skjult, bliver Natalie sendt på en undercover mission for at finde frem til om manden er en clairvoyant eller en psykotisk morder.

The team must figure out why a fisherman is being targeted and keep him from being killed.

On the 200th episode Horatio must find an attacker and save a pregnant woman and hope he has an idea as to why she was attacked.

After an explosion at a sugar refinery information about an employee an comes to light.

When the investigation of a dead millionaire leads the CSIs to an elite dating service, Ryan poses as a wealthy businessman to expose the matchmaker's lies.

Et mistænkeligt dobbeltselvmord undersøges af CSI. Sagen bliver yderligere mistænkelig, da teamet finder ud af, at det er forbundet til en bizar online kærlighedstrekant.

Memmo makes a return, bringing chaos to Miami and pitting him against Horatio in a final showdown.

When a high school bully dies as a result of a stoning, the CSIs have to find out which nerd is responsible.

The team hunt for a serial killer before he can take another victim - who may be one of the team.

The CSIs uncover an exclusive hunting club where the prey is human.

When a delivery truck driver and a housewife on his route are murdered, the CSIs try to find their connection.

An escaped prisoner takes Natalia hostage and tells her a shocking secret about his crimes.

Horatio must protect a fighter from his brother who escaped prison.

When the CSIs find a co-ed dead in a hot tub, they investigate a case marked by jealousy, psychosis and college roommates.

When Horatio chases down a mysterious murder suspect who claims he was framed, he discovers an elaborate charade.

In the season finale, Horatio must capture an escapee again when their transport plane crashes. And the team was shocked to discover that the fugitive has planned more than that.