The cast of CBS’ in-the-works CSI revival is coming into focus.

As reported in February, CBS is developing a short-run CSI revival that that would commemorate the 20th anniversary of the original series’ launch. Elementary vet Jason Tracey is shepherding the project. The follow-up would once again be set in Las Vegas and, if deals can be made, feature a number of original cast members — but which ones?

Sources confirm to TVLine that original stars William Petersen and Jorja Fox are in advanced talks to reprise their respective roles as Gil Grissom and Sara Sidle. Petersen and Fox would be surrounded by a new crop of CSI characters. An insider cautions that CBS, which declined to comment for this story, has yet to formally order the project.

Fueled by the phenomenal success of the mothership (in its heyday it averaged north of 25 million viewers), CBS went on to launch spinoffs CSI: Miami (starring David Caruso), CSI: NY (starring Gary Sinise) and CSI: Cyber (starring Patricia Arquette).

CSI‘s 15th and final full season averaged 8.3 million total viewers and a 1.3 demo rating (leading out of The Good Wife on Sunday nights), while a two-hour series-ending movie that followed that fall drew 12.2 mil and a 1.8.