Marg Helgenberger is pictured with William Petersen, Jorja Fox, Eric Szmanda and Paul Guilfoyle on the set of 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.
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— 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.