Stephen Colbert strode up to the green marble security desk in the lobby of News Corp.'s Manhattan headquarters, where in minutes he would face off with Fox News host Bill O'Reilly, the muse for the strident, preening cable pundit he plays on Comedy Central.
Suddenly Colbert realized he had forgotten something.
"Uh-oh, I don't have an ID," he said with chagrin to the skeptical woman behind the desk.
Colbert has made a name for himself by parroting the likes of O'Reilly, so much so that the top-rated Fox News host had agreed to a cultural exchange program of sorts: The comedian would stop by "The O'Reilly Factor" on Thursday, and the man he reverentially refers to as "Papa Bear" would go on "The Colbert Report" later that night.
The event -- billed by Colbert as "the greatest TV crossover since the Flintstones met the Jetsons" -- promised to be a promotional bonanza for both men.
ID or not, Colbert was ushered right in.
"Do we have a drum roll?" the Fox News host quipped as his imitator entered the studio.
The two men, both in dark pinstripe suits, shook hands firmly.
"You're going to be in character here; I'm not going to be able to get one straight answer outta ya, am I?" O'Reilly asked.
"Bill, I promise you, I'm going to mean everything I say," Colbert responded obsequiously.
O'Reilly chuckled. "I know what we're in for here."
"I wish I knew what we were in for," Colbert -- out of character for a moment -- responded with a laugh.
They commiserated about the challenges of putting together a daily show.
"It's tough being us," O'Reilly said.
The friendly behind-the-scenes banter underscored the similarities between the two savvy television personalities. While they occupy different ends of the media spectrum, both offer a perspective on the day's news sharply tailored for their audiences, often employing verbal jujitsu to make their case.
Their strategies have paid off: O'Reilly has had the No. 1 cable news show for more than five years, garnering an average audience of more than 2 million last quarter, according to Nielsen Media Research. Colbert's mock shout-fest has propelled him into the pop culture zeitgeist and earned him around 1 million viewers a night, a large share of them the young demographic coveted by advertisers.
But attracting more eyeballs in an ever more crowded media universe is a challenge, which is why both participated in Thursday's experiment in cross-pollination. Colbert helped O'Reilly draw more than 2.9 million viewers, a boost of 46% over last quarter and a hike of 67% among 25- to 54-year-old viewers.
With O'Reilly on his show, Colbert garnered 1.64 million viewers, up 50% over last quarter, and his biggest audience ever.
Those who tuned in witnessed largely genial sparring between the cable host and his satirist. O'Reilly accused Colbert of being French while the comedian noted that the Fox News commentator never gets enough credit for how loud he is. Over on Comedy Central, Colbert welcomed O'Reilly with a "Mission Accomplished" banner.
Colbert and his producers declined to discuss the impact of Thursday's shows. But O'Reilly said Friday he had received about 3,000 e-mails from viewers -- up from the usual 1,300 or so that come in a day -- the overwhelming share of them with good marks for his performance.
Still, he is skeptical that parrying with Colbert would attract younger viewers to his program in the long run.
"A one-shot thing like that won't translate to anything," O'Reilly said. "I think news programs are chasing phantoms if they think they're going to get under-thirtysomethings to watch the news."
So why do it?
"There are a lot of people in the country who hate me and hate Fox News," he said matter-of-factly. "They don't watch us and they buy the propaganda. In the sense I could reach an audience that may have not seen us, that is certainly worth it."
Dave Tabacoff, executive producer of "The O'Reilly Factor," said the cable news host's willingness to take part in Colbert's parody helped humanize him.
"I just think it shows, for people not familiar with the show, that Bill has a sense of humor, that he can make fun of himself," Tabacoff said. "There was a perception of stridency of him that was refuted."
For his part, O'Reilly said he is indifferent to his public image: "People think I'm humorless, that's fine. I don't care."
Nevertheless, he got largely positive reviews from such unlikely sources as the Huffington Post for his good-natured handling of Colbert's quips, including the comedian's display of his book "Culture Warrior," plastered with a big sticker reading "30% off" that obscured most of O'Reilly's face.
"I'm a professional; I know what he does," said the Fox News host, who said he watches the Comedy Central show. "He and his writers try to get people on there and get them off their game, whatever that may be, and see how they react. They're essentially wiseguys. So when you know that, you go in and see what they're going to do, then you counterpunch. But if you think you're going to beat him and make him look foolish, that's impossible.
"He's a very talented guy," O'Reilly added. "As long as it's not mean-spirited, it's fine."
Indeed, many of Colbert's gags were more puckish than cruel.
After "The O'Reilly Factor" taping ended, Colbert turned to his host with an odd question: "I'm going to steal your microwave oven. You OK with that?"
"Mmm-hmm, sure," O'Reilly said indifferently.
"OK, Bill says that's OK," Colbert said gleefully.
An hour later, the Comedy Central host triumphantly placed the black-and-silver microwave from the "Factor" greenroom on the bookshelf on his set.
"One can only imagine what might have been warmed in this mighty chamber," Colbert intoned. "Maybe Sean Hannity nuking a Hot Pocket. Alan Colmes reheating his mug of gruel."
Fox News officials said they didn't know about the stunt ahead of time but took it in stride. "We can always go to Circuit City and get another one," Tabacoff said.
No need. On Friday, Colbert's staff called and said they were sending over a replacement -- the Comedy Central host wants to keep O'Reilly's microwave on his set, a memento of their day.