Eight years on the night shift for the Las Vegas Police Department can take its toll on a person's psyche, even when that person is the endlessly brilliant Gil Grissom. In news that will break the hearts of millions of fanboys and girls, Entertainment Weekly's Michael Ausiello revealed this morning that William Peterson, who has portrayed CSI's lovable father figure since the show's premiere in 2000, will be leaving the CBS drama partway through its upcoming season.

"Billy is leaving," said CSI executive producer Carol Mendelsohn. "But he will remain throughout the run of the series an executive producer. And he will, whenever CBS asks, come back. I don't think you've seen the last of Gil Grissom."

Petersen himself admitted that his mid-season farewell will not be his last CSI hurrah, pointing out that he will still work behind the scenes and intends to return as a guest star every once in a while.

"I want it to work for the writers, I want it to work for the cast, and, most importantly, I want it to work for the audience," said the 55-year-old. "I don't want them to abandon the show."

Even with Petersen's upcoming departure, CSI writers have been carefully preparing for the ninth season. Former cast member and fan favourite Jorja Fox will return for several episodes, beginning with the season premiere. This will provide fervent Gil Grissom/Sara Sidle 'shippers with some much-needed closure, which will be directly responsible for a dramatic decrease in CSI fanfic.

Despite apparently being shot to death in the last season finale, Gary Dourdan will also appear in the ninth season premiere, although producers remain mum on whether or not his character will die before the end of the episode. Our money's on him kicking the bucket – call us cynical, but Dourdan's April arrest for alleged drug possession probably hasn't endeared him to the CBS higher-ups.

CSI bigwigs are also beginning a search for Petersen's eventual replacement. The character is described as a professor with a background in pathology who, at first, only helps out during a two-part episode but soon becomes a full-fledged member of the team. Producers are swinging for the fences on this, putting big-name actors like Kurt Russell, Laurence Fishburne and John Malkovich on their wish lists. Well, OK, not "swinging for the fences" so much as "offering a life-boat to actors who could use the career bump."

© (c) CanWest MediaWorks Publications Inc.