LOS ANGELES (CBSMiami) — Marg Helgenberger’s final night on “CSI” has arrived.

The actress will depart the series after 12 seasons when her final episode airs Wednesday at 10 p.m. on CBS.

Helgenberger, 53, has played investigator Catherine Willows since “CSI” debuted in 2000. She wrapped her final episode in December. Willows is leaving the CSI team for a federal post in Washington and for Helgenberger, it means saying goodbye to a role of a lifetime.

“It’s hard to comprehend. It’s been a fifth of my life. It was something that was extra rare in television,” said Helgenberger.

“From the pilot on, it’s been really touched with magic dust and I will be lucky to have another experience in my lifetime. That’s what I’m feeling.”

During her time on CSI, Helgenberger has seen it all.

“All the different canyons we’ve shot in to all the different disgusting strips, clubs, skanky alleys and landfills.”

She also laughed and said, “I won’t miss swabbing somebody’s mouth, that’s for sure.”

In an interview with The Associated Press earlier this month, the actress said she’s looking forward to time off, hiking with her dog and even looking for work. She said she’d love to do Broadway.

Helgenberger’s final episode, which is titled “Willows on the Wind,” airs two days after she received a star on the Hollywood Walk of Fame. Co-stars and friends in attendance included Dana Delaney, Ted Danson, Jorja Fox and producer Jerry Bruckheimer.

Her departure is the latest in a series of cast changes for “CSI.” Danson came on at the beginning of this season, after Laurence Fishburne left the show. Elisabeth Shue will join the cast next month as Julie Finlay, a new recruit fresh from an anger management course.

But this might not be goodbye forever – Helgenberger said she’d be willing to return to the show in the future, for a special episode or two.

“Oh, absolutely, in fact that was one of the reasons why it was a little easier for me to leave the show because the producers said to me practically every day the door is wide open. If I’m available and I’m up for it you betcha.”