It is 10 p.m. on a Tuesday and Fun. are eating steaks beneath the vaulted ceilings of the Grand Central Oyster Bar, tucked away at a corner table and merely an afterthought to the commuters finishing drinks in time to catch the 10:22 to New Haven or the 10:34 to Chappaqua.

It's been a long day for Nate Ruess, Jack Antonoff and Andrew Dost (longer, one can assume, than the guys in business suits double-fisting Johnny Walker neats at the bar), who played a sold-out show at New York's Terminal 5 last night, slept in their own beds for "the first time in about five months," and have spent every minute since shooting their "Carry On" video, which has taken them throughout the city's darkened haunts and will continue to do so until very early tomorrow morning, when director Anthony Mandler finally decides they've had enough.

So, in short, they don't seem to mind the fact that, at this moment, they are about the furthest thing from the center of attention, lost in the hustle and bustle of the world's largest railway station. They crack jokes (mostly of the knock-knock variety, all of which end with "Joe Mama,") pick at their rapidly cooling slabs of meat — someone has also inexplicably ordered eggs Benedict — and essentially try to disappear into the background.

Yet soon, the restaurant is cleared, Mandler springs to action — he shoots a large portion of the video himself, using a shoulder-mounted camera rig — extras are strategically placed throughout the Oyster Bar's famed serpentine service counter, and Fun. are put back to work. As Mandler calls out instructions, Ruess asks "Would it be better if I sat in the middle, for cross-talking?" (Mandler agrees) and the set whirs to life, a picture-perfect re-creation of New York City at its most magical, when most folks are asleep and yet there are still unending possibilities ahead.

"We've been all around New York City, just been getting really great shots of New York, and one of the cool things about that is everywhere we've been weve just been like 'This is beautiful,' " Ruess tells me. "But it could really be any location in New York, and that's the great thing about [the city], and that's the cool thing about being home: somehow everything works as a beautiful backdrop for this video."

It is now 12:42 a.m. on a Wednesday, and Ruess is sliding through the (mostly) empty concourse of Grand Central, like a figure skater in tightly-pegged trousers. The last train of the night — the 1:56 on the Harlem line to Southeast — has yet to arrive, and a few wide-eyed stragglers watch the scene with bleary-eyed disbelief ("Is that the 'We Are Young' guy?" one gentleman in a Yankees jersey asks no one in particular). In a video filled with stirring, silent moments, this is perhaps the quietest and most affecting of all, Ruess gliding through the cavernous hall, taking in the immensity of his surroundings, Mandler giving him occasional instructions but mostly content to let the scene play out naturally.

"This is really amazing," Ruess says between takes. "I mean, I don't know what to say."

So he doesn't say anything else. Instead, he's whisked outside, re-joining Antonoff and Dost on the corner of 42nd and Vanderbilt, where they're plotting one more bit of "contrived delinquency": an assault on an eagle statue that solemnly stands guard high above it all. It is 1:16 a.m. and Dost is now attempting to climb the stone beast, while the usual assortment of drunks and beautiful girls and oddballs in trenchoats cheer him on. Vendors pour hot dog water into sewer grates, and Ruess poses for pictures with fans (he tells one particularly stricken girl, "Relax, I'm not a celebrity") and just as Dost is about to reach the tufted head of the eagle, someone with his label decides this is probably not a good idea, so the whole thing is called off. So instead, Fun. dart into traffic, tossing pretzels at one another while Mandler cackles and said label rep looks on bemusedly.

It is 2:18 a.m. now, and after being packed into a waiting van, Fun. arrive at the video's final destination: New York's vaunted Old Town Bar. At this point, they are beyond tired and, truth be told, a little loopy, which is probably why, as they sit at the mahogany and marble bar, things get a bit heated. Seems Mandler is an avowed Los Angeles Lakers fan, while Ruess is a supporter of the Toronto Raptors (he became a fan of the Phoenix Suns while living in Arizona, and followed GM Bryan Colangelo to the Raps because "he knows how to build a team"). Kobe Bryant's name is used in vain, whiskeys are downed, and the whole thing ends with both men agreeing that they hope the Miami Heat don't win the NBA title (sadly, they would).

Then the action moves to the Old Town's tiny back room, where Ruess sits at a rickety piano and bangs out the chords of the song, while his bandmates — and an army of tireless extras — sing along lustily. There is some stunt booze in play here, but mostly, it is the real deal being poured, which undoubtedly explains the mood. Inside the bar, the feeling is warm, electric even, while outside, a garbage truck rattles by on its rounds. At this moment, in this city, Fun. are the only show in town.

It is 4:45 a.m. and the shoot is still going on. At this point, I depart, leaving Fun. to continue on. The "Carry On" video would wrap production at 6 a.m., at which point, presumably, the band would get to sleep in their beds one final time before heading back on the road, in support of their Some Nights album, which has not only made them stars, but made this video possible in the first place.

The next morning (or, more accurately, afternoon), I receive an email from Ruess, who begins with "I'm alive!" and ends telling me he's looking to watch the NBA Finals that night a bar with "drinks and enough isolation to listen and yell at the refs." Sadly, I end up bailing on watching with him, though he later assures me he most certainly caught the action. Which isn't surprising ... after running roughshod through the city that never sleeps, he didn't need much shut-eye of his own. For one night, at least, his band were the Kings of New York, majestically, magically so. But now, as always, the show must go on.

What do you think of Fun.'s "Carry On" video? Leave your comment below!