|Original Airdate||November 6, 2006|
|Previous Episode: Curse of the Coffin|
|Next Episode: Darkroom|
High Octane is the seventh episode of season 5 of CSI:Miami.
After an accident where the driver was decapitated during a dangerous stunt, the evidence leads the CSIs to believe it was more than an accident. While gathering the evidence, the CSIs find they must go into the world of "sideshows."
A stunt show on the streets of Miami known as a 'sideshow' turns deadly when one of the racers is decapitated while shouting a victory cheer as he speeds towards the crowd. Though the direct cause of his death is obvious--a cable with lights on it severed his head when he sped past it--Horatio thinks the nineteen-year-old, Dexter Gilman, is the victim of foul play. Delko sends a man named Mike Doyle, a documentary filmmaker who wants to follow the team, away when he catches him at the scene, but Ryan agrees to let the man follow him around in the hopes of taking heat off the lab. Alexx confirms the decapitation is what killed Dexter, but also notes a tire tread on one of his legs, indicating he was run over after he died.
The car Dexter was driving when he died is traced to a wealthy young woman named Brynn Roberts. Brynn tells Calleigh she dated Dexter and sponsored his stunts. Her father promised to double whatever money she made by the age of 25, and Brynn intends to collect. She tells Calleigh the car was stolen after Dexter was killed, and refuses to turn over her PDA. Delko turns to the discarded beer bottles at the site of Dex's death and finds an unusual print on all of them, indicating one person was handing out beer at the gathering. That person turns out to be Evan Dunbar, a teen who watched the stunts in awe. He denies stealing the car, but refuses give up the names of the other people at the sideshow. Horatio does some digging around and discovers Evan's father, Steve, was the one who called the cops on the sideshow after hearing his son talk about it.
Calleigh and Dan Cooper view footage from the sideshow released onto the internet by Brynn and notice that Dex's car was elevated when he hit the wire, indicating the hydraulics in his car were activated. Malfunction or murder? The car is recovered at another sideshow in the possession of a man named Luke Baylor, who claims to be a friend of Dex's. Half a dozen other stolen vehicles are also found at the sideshow. Tripp and Horatio suspect a car theft ring. Ryan is fairly certain Dex was murdered when he discovers a transmitter in the car, which would have allowed someone to activate the hydraulics remotely. Ryan and Delko go to question Evan Dunbar only to see the teen race by them in a car and crash. He's wounded, and the CSIs smell jet fuel in the engine. They trace the fuel to an underground line and discover an exposed pipe in the backyard of a Miami resident. The woman was having her pool worked on by none other than Steve Dunbar, Evan's father. Ryan finds Dex's blood on the gas pipe, puzzling him as the murder took place miles away. Tripp tells Horatio that the number of stolen cars in Miami has gone up in the last few weeks.
Delko discovers the remote transmitter was activated by a cell phone, and the number traces back to Brynn Roberts. Unrepentant, she says she only meant to cause Dex to crash for the attention it would bring to the sideshow, not to kill him. Calleigh is disgusted. The CSIs learn that Luke was the one who left Dex's blood on the gas pipe after shoving Dex's body out of the car and driving off. They follow him to an airport hanger where they discover him with several stolen cars. The find the ringleader, Steve Dunbar, close by, loading cars onto a plane and he is arrested.
- David Caruso as Horatio Caine
- Emily Procter as Calleigh Duquesne
- Adam Rodríguez as Eric Delko
- Khandi Alexander as Alexx Woods
- Jonathan Togo as Ryan Wolfe
- Rex Linn as Frank Tripp
- Eva LaRue as Natalia Boa Vista