Eric Szmanda

A mother thought to be grieving for the loss of her family three years ago becomes a suspect in a CSI investigation.

As CSI enters its 12th season, the team is still recovering from the fallout from the Nate Haskell case several months after its completion. Ray Langston has been let go and a new CSI supervisor, D.B. Russell, played by Ted Danson, has been hired. The Las Vegas crime lab also welcomes another new addition, a young CSI from Los Angeles and Ecklie's estranged daughter, Morgan Brady. The team must build new relationships as they solve cases that include a multiple homicide on a Vegas tram and a "Strangers on a Train" type case where numerous suspects who seem to be unrelated confess to murdering a family.

Season 4 begins with terrific back-to-back episodes involving serial killers. There's a new politically minded sheriff in town and he's ticked off that the CSI's can't get enough evidence to convict a rapist/murderer. Also, Nick and Sara buck for the same promotion. Along the way there are plenty of quirky cases: one involving a museum robbery and one involving a dead juror. Grissom travels to a small town with plenty of secrets to solve a murder, Catherine dates a younger man, and Sara works a case involving a woman strikingly similar to herself. There's also plenty of kinkiness and tragedy.

Some provocative episodes from Season 5 of CSI involve Russian mail order brides ("Nesting Dolls"), infantism ("King Baby"), and the Mexican lifestyle of narcocorrido ("Snakes"). From the creative storytelling ("4x4") to the macabre ("Who Shot Sherlock?"), there's something in Season 5 for everyone. The CSI team investigates many crimes that hit close to home as well. Grissom comes under fire from Ecklie ("Mea Culpa"), Brass tracks down his estranged daughter ("Hollywood Brass"), and during the course of the season Greg Sanders completes his transition from the lab to the field.

Arguably the best season ever, season two of CSI: Crime Scene Investigation continues to push the limits of its creative potential while simultaneously educating the viewing public into the wonders of forensic science. The season premiere (Burked) reminds us of how old Las Vegas used to be. Throughout the season, an abundance of tragic cases unfold including a high-school shooting (Bully For You), an agoraphobic victim (You've Got Male), and evil children (Cats In The Cradle).

Season 11 of the hit drama CSI picks up where it left off - with Langston on the floor of a jail cell bleeding profusely - and ends with the team solving the mystery surrounding the explosion of a van during a funeral ("Shock Waves"). Future episodes contain grisly crimes involving a shark attack in the crowded pool of a casino ("Pool Shark") and the decapitation of a young man found in the woods ("Blood Moon"). Other cases involve the knife attack of a legendary vegas icon ("Sqweegel") and the CSI's reopen a cold case involving two young girls who went missing five years ago.

Things turn a bit darker during Season 3 of CSI: Crime Scene Investigation. A cheerleader turns up disemboweled, a real murder is filmed, a taxi driver is beaten to death by a mob and a human arm is found in a meat grinder. Other standout episodes include a mysterious magician, a boxing match ending in death and a group of bitter comedians. Warrick continues to cultivate his defiance for authority, there's another case involving Lady Heather, Sara asks out Grissom and there's an explosion in the lab, Catherine learns more about her mom's ex-husband and Grissom's hearing loss becomes more problematic.

The CSIs face a year of challenge and change as they say goodbye to some of their long-time team members and welcome new ones to the night shift. Grissom, Catherine and the rest of the group deal with the aftermath of Warrick Brown's shooting, and then must adjust to the irreverent personality of new CSI Riley Adams (Lauren Lee Smith). Later in the season, the team will be in for a shock when revered leader Gil Grissom bids goodbye to Vegas and a new CSI, simply known as "The Professor," (Laurence Fishburne), joins their ranks.