NCIS, which this week starts its seventh season on CBS, seems a little old to be bearing offspring. On the other hand, the show has shown surprising ratings resilience in the past couple of years.

That vitality, as much as anything else, accounts for the birth of NCIS: Los Angeles -- and with it the show's official designation as a franchise. It premieres at 10 p.m. EDT/PDT on Tuesday.

NCIS: L.A., like its parent, relies on a sturdy, mostly youthful cast, sporadic action, and sprightly dialogue. It courts younger-adult male viewers, and in that vein, the spinoff is a chip off the old block. Chances are, it will enjoy some serious audience flow. Also, a similar dearth of Emmy nominations.

Looked at in isolation, though, NCIS: L.A. is little more than an updated version of The A-Team of the 1980s, with more high-tech gadgetry and fewer explosions. There is the same lighthearted approach to life-or-death situations. Maybe the biggest change is that NCIS: L.A. achieves its inevitably favorable outcomes with a little more intellect and a little less testosterone.

The foundation for this new series was poured in the final two episodes of last season's NCIS. The premiere takes place four months later when a barely recovered Special Agent G. Callen (Chris O'Donnell) returns a month early to resume assignments with partner Sam Hanna (LL Cool J).

Their first job is to get to the bottom of the murder of a Navy intelligence officer held hostage and killed by a Mexican drug cartel gunman about to lose his own life in a shootout with police. The NCIS agents prefer to do their investigating by pretending to be other people (real estate agents, satellite brokers and so on), even when, most of the time, the information they seek would be available without any subterfuge. It's good for the lighthearted banter.

The plot is thin, and some of the performances are threadbare. There are flashes of Los Angeles landmarks but no real attempt to give the show a Southern California vibe. Except for the occasional flash of recognizable scenery, this could be NCIS: Lubbock.

O'Donnell conveys a little more depth to his character than can be found on the printed page. The burning mystery of his bullet scars apparently will be explained in episodes reserved for sweep periods, along with the bigger mystery of why he has just an initial for a first name.

The most interesting actor to watch is veteran Linda Hunt, who plays Henrietta Hetty Lange, a combination mother hen and stern office manager. I'd love to see her on an assignment in the field.