The 12th season concludes with the CSIs investigating the murders of three people whose bodies are found a few blocks away from the site of a campaign dinner.
Dune and Gloom
When a bomb kills an off-road race truck driver mid-race, the CSI team is called on the scene.
A man Nick helped put in prison gets his conviction overturned and will be released, unless the CSIs can uncover evidence to prove he is guilty.
A man is gunned down in a casino at point-blank range, and the CSIs shut down the building to find the killer.
Malice in Wonderland
A murder and a robbery at an "Alice in Wonderland"-themed wedding are investigated.
Trends With Benefits
A college student is murdered, and her death photo ends up trending on the Internet.
A blackout cripples the city and forces the CSIs to revert to old-school methods to solve the case of a missing child.
When a house is stolen completely off its foundation, the CSIs are on the case in search of answers.
Russell asks for advice from a former colleague on a case involving the death of a man's ex-girlfriend. Elisabeth Shue joins the cast.
Tressed To Kill
When woman dressed in vintage clothing and sporting a hairstyle from the 1970s is found dead, the team discovers clues that lead to a killer with a hair fetish.
When Dr. Robbins' wife finds a nude corpse in their bedroom, it begins an investigation.
Crime After Crime
After three seemingly unrelated murders occur, the team uncovers a plot for revenge.
The CSIs discover a brain without a corresponding body at a crash site; D.B. Russell worries about his son's future.
Freaks & Geeks
The murder of a popular sideshow performer sends the team behind the scenes at a carnival freak show.
When a hijacked medevac helicopter with CSI Brody aboard goes missing, the entire team is on hunt.
Nick visits an art exhibit on a date and realizes that one work of art contains decomposing body parts.
When three people confess to killing a family, the team must decide who is telling the truth.
After multiple attacks on a public tram, the team has just one witness and a lot of questions.