Source : TV Guide – Keck’s Exclusives : CBS Press Tour Party Scoops

CSI show runner Carol Mendelsohn tells me Bill Irwin will be reprising his role as inmate Nathan Haskell in the show’s 11th season premiere, then return for three additional episodes in a story arc that will finally introduce the wife of Laurence Fishburne’s Dr. Raymond Langston. “Toward the end of the season, Mrs. Langston will play a pivotal role,” says Mendelsohn. Plus, hearing that Marg Helgenberger has decided to end her long run as Catherine Willows this season, Mendelsohn says she plans to “start begging on my knees as the season progresses. No one ever leaves the CSI family, so we’ll see.” Finally, Mendelsohn has been speaking with Jorja Fox (Sara) about how to explain to the audience why Sara has been apart from her husband Grissom for so long. Unfortunately, she has so far been unsuccessful in her repeated attempts to sway William Petersen back for a guest spot to explain the divide.