'CSI' establishes smooth order of succession

"CSI: Crime Scene Investigation" has already branched out with two successful CBS spinoffs. Now the original series has to see if it can regrow itself after lopping off its lead actor.

And with Laurence Fishburne joining the cast, it looks as if it can and will remain vital.

As Chicago theatergoers already know, "CSI" star William Petersen has returned to the town - and the stage - where his career first flourished. He's playing out the run of "Dublin Carol" at Steppenwolf, where he's also just been accepted into the ensemble, and he's already slated to do another play next summer for Victory Gardens.

That doesn't leave much time to jet-set back to El Lay to play Gil Grissom in "CSI," but stardom - at least, the Hollywood sort of stardom - has never seemed to sit well with Petersen. He probably could have joined the ranks of hunky leading men after "Manhunter," but he just sort of let that opportunity lapse, and while he has brought quirky nuances to the role of Grissom in "CSI," that sort of autopilot acting doesn't seem to interest him much either.

So he's leaving the show, but unlike, say, Rob Morrow in "Northern Exposure," he's not gutting the series in the process. Petersen will continue to produce "CSI," so it's in his interest to make a smooth transition to create space for another lead actor.

The quality that has always set "CSI" apart from other more gratuitously gruesome TV whodunits is its no-nonsense efficiency, the way it watches its actors do their work, even as they concentrate on the fine details of crime detection as played out by their characters. So in a nifty bit of life-meets-art, Grissom announces he'll be leaving "CSI" in today's episode at 8 p.m. on WBBM Channel 2, even as Petersen welcomes Fishburne in as his heir apparent, Dr. Raymond Langston, a university professor with a specialty in serial killers.

Again, there's no gratuitous showboating. In fact, tonight's episode is noteworthy for the way it works the Grissom-Langston transition into a challenging new "CSI" case. A murder seems to suggest that the notorious "Dick & Jane Killer" is back in action, but he's actually already in jail. Is there a copycat or some previously unknown accomplice carrying out new crimes? Dr. Langston just happens to have a regular teleconference set up with the "DJK" (don't you love that flair for police argot?) for his class on serial killers, so Grissom slips in to monitor it - and confront the original killer with some probing questions. Not to give anything away, but after Grissom announces his intention to leave tonight, he and Langston will work together on the revived DJK case until Petersen formally leaves the series in an episode now set for Jan. 15.

What's interesting for now is the way Grissom and Langston develop a rivalry, but also a mutual respect, and that seems true to both of the characters and of the actors playing them. "CSI" needed a star with a certain gravitas to fill the void to be left by Petersen, and Fishburne fits the bill (even if I remember first seeing him as Cowboy Curtis on "Pee-wee's Playhouse," just as I remember first seeing Petersen play Captain Ahab in the Remains Theater production of "Moby Dick"). Despite intense competition, "CSI" remains the top-rated show on Thursdays, having pulled in 17.5 million viewers last week, and Fishburne seems as likely as anyone to retain that audience.

After all, "CSI" has never been a one-star series. It has built up, and rebuilt, a fine ensemble cast over the years, and they'll continue to carry much of the weight.

The other thing I like about the way "CSI" is handling Grissom's departure is the way it's being left a little vague. The side characters speculate tonight about the true reason Grissom is leaving, but he never makes it plain. It's as if he were just interested in going off and doing something different for a while, which indeed he is, as long as it's understood that the "he" in question is Peterson. This way, he could opt to return at any time as well.

Marg Helgenberger's Catherine Willows might not know any more than anyone else does about Grissom's motives, but she sure had an inkling. "I knew before you knew," she tells Grissom. Sometimes a man's just got to up and go, and perhaps Helgenberger sensed that in Petersen even before he did.