Fox crossed "The Big Chill" with the CBS hit "Cold Case" and got a two-ton frozen turkey. Actually, that weight estimate may be high, because "Reunion," a kind of nostalgic musical murder mystery, is lighter than air, but less substantial. The ill-fated actors go through their motions in a way that suggests hamsters spinning in a wheel or rats navigating a maze. They are trapped by, virtually enslaved by, the show's gimmicky gimmick: Each episode will be based in the present but will flash back to an earlier year in the lives of six dreary drips who vowed in high school to remain friends forever.

In the premiere, at 9 tonight on Channel 5 (following the season debut of "The O.C.," whose youngish audience is obviously "Reunion's" target), we attend the funeral of one of the friends in Bedford, N.Y., circa 2005. We are not told -- yet, anyway -- which of the gang has died, although a eulogy notes that the poor sap didn't just pass away but was "brutally murdered." A bit of bad luck, that.

Then comes the first flashback: to Graduation Day 1986, when pals Aaron, Samantha, Will, Craig, Carla and Jenna live through experiences that, unbeknown to them, are going to "change those six lives forever." Being brutally murdered is certainly a major life change, but there are plenty of subplots along the way. These complications give us a chance to get to know the characters and how they relate to one another -- definitely not the chance of a lifetime.

The second episode will flash back to 1987, the third to 1988, and so on, with the finale being the 20-year reunion of the Class of '86. If it all sounds tritely and tediously tidy, it is.

"May everything always stay as perfect as it is right now," one graduate says in a toast. The concept of appearing to be perfect is almost a theme of the premiere. "I'm a sucker for perfection," anxious Aaron (Dave Annable) says of the allegedly fantabulous Jenna (Amanda Righetti), after whom Aaron lusts longingly but listlessly.

Samantha (Alexa Davalos), having taken a home pregnancy test, complains it's "not exactly perfect timing" to have possibly become pregnant upon graduation, and her friend Will (Will Estes) repeats the "perfect timing" remark as if there'd been something witty about it. Anyway, it turns out that perfection is in no way a theme of the show, except to the extent that it could be the polar opposite of it.

As 1986 plods on -- to such fondly remembered hits of the era as Cyndi Lauper's "Time After Time" and Madonna's "Papa Don't Preach" -- friendships are tested in big, big ways. Rich, smug Craig (Sean Faris), who looks so much like Tom Cruise that the resemblance is written into the script, smashes his Porsche into another car, suffering only a minor injury but finding himself facing arrest for driving while intoxicated. His super-swell honey-buddy Will, sitting in the passenger seat, had not been drinking heavily and so agrees to say that he, not Craig, was driving. But there's a big fat "oops" around the next curve: The driver of the other car dies, and Will faces a charge of manslaughter.

Lawyers work out a plea bargain arrangement that will let Will off with a community service sentence, but then -- like an anvil falling from the sky in a Road Runner cartoon -- another oops plummets. Mainly out of meanness, the judge throws out the arrangement proposed by the lawyers and sentences poor Will to 12 months in a county prison.

Now that could put a real strain on a friendship, eh? But wait. In a tired example of tit trumping tat, it turns out that all this time Will, Craig's addled ally, has been secretly dating Craig's fanatically beloved and possibly pregnant Samantha. Talk about your sticky wickets. One minor mystery, to supplement the major matter of who died and who the killer is, is what's up with Carla (Chyler Leigh). There are indications in the pilot that she may be attracted to a fellow female classmate, perhaps a provocative touch 10 years ago but pretty de rigueur now.

Being assigned to play vapid, torpid characters was hardly an insult to the six young performers who tread through the mish-mosh, but a very good actor, Mathew St. Patrick, has been reduced mainly to lurking in the background, emerging on occasion to ask questions about the murder. St. Patrick has suffered enough onscreen; previously he spent five seasons as Keith, the inexplicably loyal life partner of whining David (Michael C. Hall) on HBO's recently departed "Six Feet Under."

St. Patrick brought command and dignity to the role of Keith, and he tries to do that again as the cold-case opener on "Reunion," but it's the ultimate example of "to no avail." It's hard to imagine that viewers will be dying to learn which graduate kicks the bucket on "Reunion," mainly because none of them gives the appearance of being, or ever having been, alive.

Reunion (one hour) begins tonight at 9 on Channel 5.

Least likely to succeed: Sean Faris and Alexa Davalos of Fox's brain-dead nostalgic murder mystery "Reunion."Pretty good friends: Will Estes and Sean Faris, above, and Amanda Righetti are half of "Reunion's" insipid '80s sextet. On tonight's premiere, the Lacoste era.