Ted Danson and Elisabeth Shue in "CSI: Crime Scene Investigation"

Twelve years ago, CBS broke new ground with a series about the scientists behind crime investigation. "CSI: Crime Scene Investigation" mixed the drama of a police procedural while providing factual research and situations. The series was welcomed in 2000 with open arms by viewers because many of the other premieres of the season were either sitcoms -- "Curb Your Enthusiasm," "Yes, Dear," "Malcolm in the Middle" -- or reality series, such as "Survivor" or "Big Brother."

"CSI" developed such a following that it spun into two other series, which both met with equal success. Without trying to recreate the same characters in a different city, as many spinoffs have tried, the franchise makes new characters and new situations in a fresh environment.

On Wednesday, Feb. 15, Elisabeth Shue will join the cast as Julie Finlay, who has a mysterious past with supervisor D.B. Russell (Ted Danson) and has just left a court-ordered anger management course. Shue steps onto the set only two episodes after Catherine Willows (Marg Helgenberger) left the team."CSI: Crime Scene Investigation" airs Wednesdays on CBS.

Shue has had a wide array of roles during her career, and though most of them are in film, there is no doubt that she will be an asset to the "CSI" cast. Shue's career started back in 1984 when she played the love interest in "The Karate Kid," but it wasn't until her award-winning role in 1995's "Leaving Las Vegas" that she started to be noticed. She has also starred in "Hollow Man" (2000), "Hide and Seek" (2005) and "Tuck Everlasting" (2002).

Shue has little experience on the small screen, having only appeared in a short-lived ABC comedy in the mid-'80s, "Call to Glory."

Unlike the other departures the team has endured over the years, Willows's resignation was expected and, as Helgenberger herself said, "inevitable." Willows decides that it is time to say goodbye when she is demoted, and she and her new supervisor (Danson) are constantly butting heads.

"There is a little resentment, but Ted's character so far is endearing and has a unique way of looking at a crime scene. It's a nice, fresh perspective and it kind of gets under everyone's skin a little bit, in a good way," Helgenberger said in an interview with E! Online. "I think Catherine is very intrigued by him. I think ultimately Catherine is a team player and they took some liberties last season the way the crime came about or was solved and she was willing to admit it. And this is the fallout."

Helgenberger has expressed interest in returning for the occasional plot line, so we may see her again.

The series has had multiple main characters come and go and, in some cases, return. Even in the pilot episode, new criminalist Holly Gribbs (Chandra West) was shot and killed during her first day on the job. After setting this precedent, the writers left viewers on edge about what would happen with the characters they have grown to love. Gribbs was replaced by Sara Sidle (Jorja Fox).

In Season 5, Nick Stokes was taken hostage by an irate father who wanted revenge for his daughter's incarceration. Though Stokes lived after being buried alive, viewers were on the edge of their seats to see what would happen to the character.

It wasn't too long before the series said farewell to another star, when Sidle is kidnapped by the Miniature Killer and almost killed. She later left the show, but she returned after Warrick Brown (Gary Dourdan) was shot and killed at the end of the season.

The team's original supervisor, Gil Grissom (played by William Peterson) left the lab after Brown's death, but he still appears periodically as Sidle's new husband. When Grissom left, Dr. Raymond Langston (Laurence Fishburne) took over for two seasons. At the beginning of this season, Danson joined the cast as the new supervisor, D.B. Russell.

There have also been several short-term additions to the team, including Riley Adams (Lauren Lee Smith), Ronnie Lake (Jessica Lucas) and Mike Keppler (Liev Shrieber), but all came and went rather quickly.