LOS ANGELES - Ron Swanson, Pawnee's most antisocial middle manager, had visitors in his office, a rare occurrence that he commemorated by swiveling the sawed-off shotgun on his desk toward my private parts.

"I'll just clip a kidney," he said in a way one might order an egg-salad sandwich.

I figured this was as good a time as any to notify Nick Offerman, who portrays Swanson, that he's the finest actor since Laurence Olivier and that his sitcom, "Parks & Recreation," should be declared the eighth wonder of the world.

Actually, you don't have to put a gun barrel to my gonads to get me to say that "Parks & Recreation," which returns to the air Thursday after an eight-month absence, is TV's most improved series, with a cast of lovable losers as engaging and sympathetic as the regulars at Cheers or the drivers at Sunshine Taxi Company.

"We found our stride last season, and we've just been rolling ever since," said Offerman, who deserves an Emmy nod whether he's packing or not.

When "Parks" premiered in the spring of 2009, I thought creators Greg Daniels and Michael Schur had done a disservice to star Amy Poehler, presenting her character, Leslie Knope, as a bubbleheaded blonde who was more one-dimensional than any number of her "Saturday Night Live" characters. But by the end of that initial six-episode run, Knope had gotten smarter and the rest of the cast became more than just stand-ins. That development is a vivid reminder that sitcoms, more than any other genre, take time to blossom as writers learn to play to the cast's strengths.

"If you're doing something high-concept, like a drama about aliens, audiences can get it right away, but if you're doing a character comedy, the audience needs to learn who the characters are and the writers learn as they write," said Daniels, who also helped launch "The Office," another NBC comedy that took time to find its footing. "Now Leslie Knope is more capable and more human. She gets drunk a lot."

Offerman said you shouldn't judge a book by its cover -- or even the first chapter.

"When you read the first 40 pages of a novel, you might think a guy is a jerk," he said, clearly referring to his character, a brusque bureaucrat who initially came off as a cold-hearted, disdainful bum. "But then you get to page 100 and you say, 'Oh, he was so nice to that squirrel.'"

Rashida Jones also has found more colors to paint with. Her character, Ann Perkins, was originally the show's symbol of sanity -- a person who existed mainly to do a double take every time Knope said something ridiculous. Now she is a full-fledged member of the nuthouse, thanks in no small part to her falling hard for a peppy preppie played by Rob Lowe.

"I think you've got to establish the rules in the beginning so that you can break them later," she said. "Ann was initially a bit of a doormat, loyal to a fault and kind of lame when it came to relationships. Now she's giving it back to Leslie a little bit more, has a few more boundaries and might not be totally sane."

The characters have more than romance on their minds. This week's episode, part of NBC's launch of a three-hour block of comedies, marks the start of a long, hilarious story line in which Knope bets the future of her department on the success or failure of a harvest festival.

From the half-dozen episodes I've seen, it's a brilliant step that ups the ante as well as the laughs. And, no, there's not a gun in sight.

njustin@startribune.com • 612-673-7431 • Follow Justin on Twitter: @nealjustin