I wrote yesterday that "Cougar Town" had been TV's most-improved comedy over the course of this season, but it only holds that title because all the improvement on "Parks and Recreation" happened in between seasons.

When the show debuted last spring, it came across at times like a watered-down imitation of "The Office" (where creators Greg Daniels and Mike Schur previously worked), with Amy Poehler's Indiana civil servant Leslie Knope seeming broad, clueless, and pathetic.

But when "Parks and Rec" came back in the fall, Daniels, Schur, Poehler and company had recalibrated everything just enough that the series went from not really working to the funniest, most consistent show on NBC's Thursday night schedule. (Weekly, "Parks and Rec" and "Community" put their older counterparts at 9 and 9:30 to shame.)

Where Leslie's enthusiasm and absolute faith in government was something to be pitied in the spring, it was now something to be admired. Where her co-workers used to joke about her behind their backs, they now respected and even feared her superhuman energy level. Where it made no sense why nurse Ann Perkins (Rashida Jones) would want to spend time with this loon, it now became clear that Leslie provided some stability to her life. Etc.

Everything about the character rotated just enough that what had been frustrating became funny. And Leslie's newfound humanity in turn allowed the writers to dig deeper into their bench. As Ron Swanson, the mustachioed, government-hating, breakfast food-loving head of the parks department, Nick Offerman has been offering a weekly clinic in the comedy of minimalism, and the writers have found a way to turn Ron's absolute manliness into both a running gag and a trait worthy of celebration. Ann's loser musician ex-boyfriend Andy (Chris Pratt, deservingly promoted from guest star to regular) cleaned up his act, got a job and became shockingly likable without loosing his hilariously childlike view of the world, and he was then paired with Aubrey Plaza's deadpan April in a charmingly low-key Will-They-Or-Won't-they situation. The city of Pawnee has started to become a character on the show akin to a live-action Springfield, with characters like smug public access talk show host Joan Callamezzo (Mo Collins) or smarmy Jean-Ralphio (Ben Schwartz) popping in and out of the show as needed.

While "The Office" has struggled this year (in part, no doubt, because Daniels and Schur are busy elsewhere), "Parks and Recreation" has filled the void, neatly balancing broad comedy (a rampaging possum, Ron having an inappropriate reaction to a shoeshine) with warmer character arcs (like Ron and April's unlikely surrogate father-daughter relationship).

But all that creative improvement hasn't been reflected in the ratings. NBC ordered another season of the show (which is being rushed into production so as much as possible can be filmed before Poehler has another baby), but the overall numbers still aren't great. Maybe it's because potential viewers sampled the show last spring and didn't like it, maybe a show about civil servants isn't as innately appealing as one set in a more generic office, or maybe NBC has done the show a disservice by airing it before "The Office" and not after. Where "30 Rock," which has that protected 9:30 timeslot, clearly has as big an audience as it's ever going to get, "Parks and Rec" still might have potential to grow.

And in trying to help the show grow, tomorrow night's episode brings the arrival of two significant new characters: a pair of government auditors, played by Rob Lowe and Adam Scott, who have been brought in to help Pawnee solve a major budget crisis.

Lowe has developed some strong light comedy chops over the years and is put to good use as the pretty face of the operation, while Scott does all the work. In some ways, it's a meta-commentary on their new positions within the show: Lowe is the bigger name whom NBC obviously hopes will attract more viewers (saving the show just like his character is trying to save Pawnee), while Scott (the leading man of Starz's hilarious "Party Down") gets to carry more of the load with his appealingly dry sense of humor.

Based on the failure of Lowe's star vehicles in between ensemble turns on "West Wing" and "Brothers & Sisters," I'm not sure how much he moves the ratings needle anymore. But anyone who can bring more viewers to this superb comedy, while fitting in nicely as a character and not a ratings stunt, is more than welcome.

Alan Sepinwall may be reached at sepinwall@hitfix.com