Summer Glau

Now this is how you rejuvenate a franchise.

Smart, tough and entertaining, Terminator: The Sarah Connor Chronicles gets most everything right that Bionic Woman got so glaringly wrong.

Witty rather than relentlessly dour, exciting rather than excrutiatingly dull, Sarah Connor has the twin benefits of a more clearly defined battle between good and evil and, in Lena Headey, a livelier British star who has better mastered the demands of an action/adventure format and an American accent.

Arriving with a two-part special that concludes Monday, this latest, Schwarzenegger-free extension of the Terminator franchise occupies a sweet spot between the second and third films. You’d think that would pose a storytelling problem, since we supposedly already know from T3 that nothing Sarah Connor (Headey) does can do much good. But the TV series solves that dilemma with a clever twist that sets it off on its own timeline.

No, it doesn’t make sense, but it works well enough if you don’t look too closely. Which is good advice in general, as giving too much thought to Terminator’s ever-shifting timelines could make your head explode.

It would be better if the show made some tiny concession to those who come to the story cold, but the basics are fairly simple: In the middle of a future war between humans and robots, the bots send back a bionic "terminator" to kill the future leader of the human rebellion: John Connor (Thomas Dekker), now 15.

So future-John sends back a human-friendly terminator, Cameron (Firefly’s Summer Glau), to protect his boyhood self and his mother, Sarah.

Mom, however, has her own plan: to stop the robots from being created at all. She just has to avoid the FBI agent (Richard T. Jones) who is after her for a crime that was committed in Terminator 2.

As much as the show recalls the movies, it also recalls some of the best work ever done in the genre for TV: the Buffy universe of Joss Whedon. Most every blast of portent and bombast is lightened by a throwaway joke; scenes of intense action and violence give way to equally well-realized scenes of domestic life that root the fantasy in emotional reality.

It’s not easy, after all, to raise a teenage boy who is destined to save the universe — or to help a single-minded robot pass herself off as a teenage girl.

None of this would work nearly as well as it does if the cast were not as strong as the production values. As she did on Firefly, Glau puts an amusing, enigmatic spin on her character, and Dekker brings just the right mix of optimism and obstinence to his coming-of-age teen.

But if there’s a breakout star here, it’s Headey as a capable, sexy heroine who gets to add maternal fury to the mix.

Who needs bionics when you have a woman like that?