Share story

NEW YORK — Life comes with few chances to witness a fundamental law being turned on its head.

But last season 18.5 million viewers did just that every week, tuning in to “NCIS” to certify it as one of TV’s highest-rated shows and make it a series whose audience after 10 seasons has expanded, not shriveled, with age. “NCIS” grew by more than a million viewers last year alone.

This, of course, contradicts TV’s natural order. “NCIS” (which starts its 11th season Tuesday) seems to have a long-term lease on television’s fountain of youth.

It doesn’t hurt that it maintains an absorbing, go-down-easy recipe of drama, character and humor that no other show is able to match.

“We’ve been successful so far,” says series star Mark Harmon with some understatement, “and we keep finding ways to grow it.”

But don’t go laying too much credit for that growth at Harmon’s feet.

He’s the star, of course, playing tormented but intrepid Leroy Jethro Gibbs, special agent in charge of the military’s Major Case Response Team.

Harmon is surrounded by a sturdy troupe of actors including Michael Weatherly (NCIS Special Agent Anthony DiNozzo), David McCallum (Dr. Donald “Ducky” Mallard) and the wildly popular Pauley Perrette (as Goth lab rat Abby Sciuto).

Granted, there have been comings and goings. This summer, “NCIS” fans were shocked to learn that Cote de Pablo was exiting after eight seasons.

“We wish Cote well,” says Harmon. “But for those of us still here, it’s all about moving on: ‘This is what we’ve got, and we’re going to find a way to make it even better.’

“I’m not trying to shuck off our success, because it’s all earned, every bit of it. By a lot of people.”

Thus does Harmon re­affirm his one-for-all-and-all-for-one manifesto.

“I’m not the big dog,” he says flatly. “I might be a dog. But there’s a lot of dogs.”

Now 62, Harmon is an unlikely TV superstar. His manner during a recent interview is friendly but crisp, firmly self-effacing. His pretty-boy looks matured in middle age, and this is the all-grown-up version of the star quarterback at UCLA who, after brief turns in law school, advertising and selling shoes, set his sights anew on acting and made good.

He forged a solid career in a succession of TV series, including “Reasonable Doubts,” “Chicago Hope” and “St. Elsewhere,” where, nearly 30 years ago, he played the first prime-time hero to die of AIDS.

Still, the man crowned as “the greatest actor who ever lived” by “Family Guy” cartoon aesthete Peter Griffin never reached the top tier of showbiz, even as he weathered accolades like People magazine’s “Sexiest Man Alive” in 1986. And, as with most actors, he has also suffered setbacks, such as his ABC private-eye drama “Charlie Grace,” which lasted little more than a month in 1995.

So when “NCIS” arrived as a spinoff of the durable “JAG,” there was no reason to expect fireworks from this new venture.

“We were able to keep it afloat a couple of years because we weren’t good enough to get all the attention and we weren’t bad enough to get canceled,” says Harmon. “And the biggest thing: We shoot in Santa Clarita,” 30 miles from Los Angeles. “Nobody from the network wanted to drive out there!”