Horatio finds a body in the boot of a vehicle, but the young driver, Kevin Hensler, insists that he was held at gunpoint and forced to transport the body by a mystery man. While the CSIs check out Kevin's story, Tom examines the body. He concludes that the man, a government census taker by the name of Carl Benson, died from chemical poisoning. Natalia and Ryan visit the last neighbourhood covered by Carl. On the estate, they find an abandoned house containing traces of insulating wool that match fibres found on the victim's T-shirt. Back at the station, Kevin denies all knowledge of the house, but Tripp discovers that the young man's father owns the building. Marie, a maid at one of the neighbouring properties, seems particularly concerned about who was in the house at the time, which arouses Calleigh's suspicions. Horatio suddenly realises that the building was deliberately rigged to blow when the kitchen door was opened, and he frantically tries to get through to Jesse and Walter to call them off. However, the CSIs have turned their phones off to avoid triggering an explosion in the volatile environment. Luckily, Jesse spots the bomb and disables it with seconds to spare. Kevin claims that the man was only in the room for a maximum of 30 minutes before he died, leading Jesse to suspect that he is lying again. However, Tom confirms that he was mistaken about Carl's death - in fact, he died quickly because he ingested rather than inhaled the chemical. Tom explains that it was not the methamphetamine fumes that killed the victim, but rat poison that was forced into his mouth. After hearing this news, Calleigh notices a silk headscarf in the box of evidence from the meth lab, and immediately remembers that Marie was wearing a very similar scarf in her hair. Suspecting that it could have been used to administer the poison to Carl, Calleigh sets about questioning Marie. Could this innocent-looking maid really be a cold-blooded killer?
The team races against time to find out who is trying to frame Horatio for the murder of a woman he has been dating.
When a beautiful socialite turns up dead, the CSIs uncover a kidnapping game for the idle rich.
A gang seek revenge on a rival gang member by opening fire at a funeral. When those responsible learn that Horatio is investigating them, they order a hit on him.