AceShowbiz -

"CSI: Crime Scene Investigation" stars return to the set one last time before the show ends for good. The original cast, including Marg Helgenberger (Catherine Willows), William Petersen (Gil Grissom), Jorja Fox (Sara Sidle), Eric Szmanda (Greg Sanders) and Paul Guilfoyle (Jim Brass), have been pictured together as they're filming the series finale.

Helgenberger took to Twitter to share pictures from the reunion. "Great fun today with this gang!" she captioned the group photo. In another shot, she posed with Petersen. "#Grillows with Jorja & Paul backing us up," so she wrote in the caption.

#OGCSI Great fun today with this gang! pic.twitter.com/HHAx9norkj

— Marg Helgenberger (@MargHelgen) July 31, 2015

#Grillows with Jorja & Paul backing us up. #CSI4EVER! pic.twitter.com/jWdZOzxYC2

— Marg Helgenberger (@MargHelgen) July 31, 2015

Anthony E. Zuiker, creator of the series franchise, has also updated his Twitter with some pictures from behind-the-scenes of the series finale. He posted a picture of the script and the first shot taken on the first day of filming on Wednesday, July 29.

It begins... The first day of shooting for the CSI finale. Stay tuned! pic.twitter.com/I9paQxzCp1

— Anthony E. Zuiker (@zuiker) July 29, 2015

First shot! pic.twitter.com/FMB27uHOH2

— Anthony E. Zuiker (@zuiker) July 29, 2015

The King and I... pic.twitter.com/dE9EN0i0fM

— Anthony E. Zuiker (@zuiker) July 30, 2015

Day two of the finale. Marg Helgenberger just slaying us today. She is amazing with a Capitol Z. What a blessing. pic.twitter.com/GddNkVa4XR

  Editors' Pick

• LL Cool J and Queen Latifah Join BET’s First Advisory Board
• Cassie Permanently Leaves US After $30M Payout Linked to Diddy Abuse
• Tom Holland Says Off-Screen Bond with Zendaya Helped Spider-Man Scene
• Grammy-Winning Singer Peabo Bryson Dies at 75 After Stroke
• Bear Brown Reveals Troubling Update on Matt Brown’s Possible Death

— Anthony E. Zuiker (@zuiker) July 30, 2015

Robbins in the his-zouse. Carving them up in the auto-ziptosy. The ev is in...This is going to be off the hizook. pic.twitter.com/fNCt283gFt

— Anthony E. Zuiker (@zuiker) July 31, 2015

The master at work... Welcome back, William Petersen. Love, the CSI family. pic.twitter.com/hxidNu4k4q

— Anthony E. Zuiker (@zuiker) July 31, 2015

The greatest... pic.twitter.com/eJnpBd7pC4

— Anthony E. Zuiker (@zuiker) August 1, 2015

Zuiker additionally teased the return of Melinda Clarke, who will reprise her role as Lady Heather.

Guess who? pic.twitter.com/hIgM4Mk33b

— Anthony E. Zuiker (@zuiker) August 4, 2015

While Ted Danson (D.B. Russell), Jon Wellner (Henry Andrews), David Berman (David Phillips), Wallace Langham (David Hodges), Elisabeth Harnois (Morgan Brody) and Robert David Hall (Dr. Al Robbins) have also been confirmed to return for the two-hour finale, George Eads (Nick Stokes) and Elisabeth Shue (Julie Finlay) reportedly have decided to skip the final episode.

The farewell special is set to air September 27 on CBS.