CBS has a drama formula that's served the network very well for the past decade. It is the dominant home of procedural crime dramas on television: The "CSI" franchise. "NCIS" and "NCIS: Los Angeles." Now at least two "Criminal Minds" shows. Various non-franchised cop and FBI shows from producer Jerry Bruckheimer. It's who CBS is, it's what the network does. These aren't sexy water-cooler hits, but they get the job done and have made CBS a lot of money for years.

Clearly, though, the drama development people at CBS get itchy to try something besides the latest "Acronym: City" series. So every season, the network introduces at least one show that's pretty wildly off-brand. Some have been quite good, like "Joan of Arcadia" (teenage girl talks to God). Some have been absolutely terrible, like "Viva Laughlin" (musical casino soap opera). And many have fallen somewhere in between, like "Jericho" (post-nuclear war drama). But what they all have in common is that none perform remotely as well in the ratings, nor last nearly as long, as most of CBS' cop shows.

(Even "The Good Wife," which has very effectively married the format of a legal procedural with more ambitious, cable-like elements and is arguably the strongest drama on network TV at the moment, isn't a lock  to return for a third season.)

So I never try to get too attached to CBS' various experiments, because they usually don't last long. That's why I don't have a ton of hope for "Chaos," a quirky drama about the CIA that debuts Friday night at 8. But it seems like it could be kind of fun for however long it's around.

Freddy Rodriguez from "Six Feet Under" plays Rick Martinez, an eager, naive but not untalented rookie agent who gets assigned (by "That '70s Show" alum Kurtwood Smith at full amused glower) to be a mole in a unit whose members proudly refer to themselves as "the last of the old-school spooks," who still practice traditional espionage in the style we're familiar with from movies and other TV shows.

They're a motley bunch, including a transplanted Scotsman (James Murray) who does a good Sean Connery impression, a gangly middle-aged guy (Tim Blake Nelson) who introduces himself as "a human weapon," and a leader (Eric Close, who spent seven years on quintessential CBS drama "Without a Trace") who's "a tactical genius with a fevered brain." They're also very good at what they do. They twig almost instantly to Rick's true purpose within their midst, and are able to cobble together a mission to rescue a kidnapped journalist when the bosses - who, Close's character explains, "define success as the absence of failure" - don't want to do anything.

It's a tricky blend of styles "Chaos" is trying for. Creator Tom Spezialy ("Reaper") wants you to laugh at these guys for 3/4 of the way through the story, then be impressed when it turns out they know what they're doing. Trying to simultaneously spoof something while being a sincere and effective example of what you're spoofing can be done - can, in cases like "Galaxy Quest" or "Hot Fuzz," be pretty fantastic. But it takes a director with a firmer command of tone than Brett Ratner has demonstrated in a successful but wholly unremarkable movie career. (To borrow a Bill Simmons line, Ratner rarely takes anything off the table, but he never brings anything to the table, either.) Had Spezialy given Ratner a script that was a more straightforward spy adventure, or an unblinking spoof, he probably could have pulled it off, but instead the combo doesn't seem so much ambitious as indecisive.

Still, it's a likable cast, filled with actors who have experience in both comedy and drama (and, in cases like Rodriguez on "Six Feet" or Close's first CBS show, "Now And Again," both simultaneously), and some of what the show has to say about spy culture in the 21st century is fairly amusing. On his first day on the job, for instance, Rick is befriended by an older agent who offers to mentor him; his new teammates later explain that the guy's program had its budget taken away, leaving him without an office or assignment and desperate to get in with a different unit.

When an attractive veteran female agent (Carmen Ejogo) takes Rick out for drinks, she gives him the lay of the land - which seems about as untrustworthy as everything else Rick is told - and explains, "You've heard of office politics. Ours come with poison pills and guns."

There's a promising show here, and with time maybe "Chaos" can figure itself out. But as with all unconventional CBS dramas, time is a luxury it shouldn't bank on.

Alan Sepinwall may be reached at sepinwall@hitfix.com