Ads for tonight's "Parks and Recreation" - or, to be specific, ads for NBC's Thursday night comedies that include "Parks and Rec" - have hinted at, quote, "the arrival of a secret big-time movie star" whose face is not revealed and whose name is not mentioned. I've seen tonight's episode, and can say three things upfront: 1)It's extremely funny, and one of the best overall episodes so far about Leslie's campaign for city council; 2)The Secret Big-Time Movie Star in question is used very well; and 3)Knowing the identity of the Secret Big-Time Movie Star doesn't seem like something that would ordinarily be treated as a spoiler — especially not by the spoiler-loving NBC promo department — particularly since he appears on-camera within the first 5 seconds of the episode.

Still, if you want to know who it is, and get a very brief sense of who he's playing and what the episode is about, click on through. If not, we'll see you tonight at 8:30...

So the Secret Big-Time Movie Star is none other than Mr. Paul Rudd, who is pretty deeply connected to "Parks and Rec" due to his longtime friendship with Adam Scott(*), as well as his frequent on-screen pairing with Rashida Jones. He'll play Leslie's chief rival in the election, Bobby Newport, heir to the Sweetums candy empire that has driven stories in past episodes.

(*) Scott wound up playing the "Party Down" role originally conceived for Rudd, and the two worked together on-camera in last year's "Our Idiot Brother." 

In the episode's main story, Ben convinces Leslie that the only way to defeat such a rich and popular opponent is to hit him with a negative attack ad. This goes against everything the uber-positive Leslie believes in, and she and Ben shoot dueling ads to see whose approach is better. I will leave everything else for you to learn tonight, but prepare yourself for two things: 1)There is a scene featuring Ben, Jerry and Tom that may rival Ron's shoeshine and Chris telling himself to stop pooping for repeated hilarity (I have yet to not laugh at it despite watching it at least a dozen times), and 2)In addition to the strong campaign story, there are two terrific, funny subplots involving Andy and April going to the doctor and Chris trying to work with Ron.

Rudd has done some TV guest work in the past, including a one-episode stint on "Veronica Mars" (a show created by another old friend — and "Party Down" co-creator — Rob Thomas) and several episodes on "Reno 911." Back in the waning days of NBC's Thursday night dynasty, he spent most of the final season of "Friends" playing Phoebe's husband Mike Hannigan (or, as he is sometimes known, Crap Bag).

"Parks and Rec" doesn't have remotely the ratings that "Friends" used to get, even in that final season, but it's an incredibly worthy heir to a Thursday night comedy legacy dating all the way back to "Cheers." If I believed that stunt casting still had the power to move the ratings needle, I'd be irked that Rudd's identity is being concealed for reasons unknown, especially because tonight's episode would be a good introduction to the show for a newcomer. But nobody tunes in just for guest stars anymore — not even Secret Big-Time Movie Star guest stars — so the weird obfuscation doesn't seem that big a deal.

Still, if you happen to know somebody who loves Paul Rudd but doesn't watch "Parks and Rec," it wouldn't hurt to spread the word, I imagine.