Inside the two-story main cabin on board the S.S. Tyrannic—ringing the balcony, posted up the staircase, packed onto the first floor—a crowd of young men and women are clad in spandex suits and masks, beards and wigs, capes and facepaint. One guy carries a huge spear. They shout along to the music, hands chopping through air. A man with a quiver of arrows slung across his back shifts his longbow to make way for an oversized milkshake dancing his way through the balcony. It's the weekend of Comic Con in New York, and the party is in full swing on Adult Swim's three-hour tour up to the George Washington Bridge, then down to the Statue of Liberty.

Right at the center of this torrent of costumed insanity, Jaime "El-P" Meline, in denim and a fitted New York Yankees cap, stands next to "Killer" Mike Render, in all black, on a small patch of hardwood. "We came dressed as Run the Jewels," El jokes. Behind them, their DJ wears a hat that reads "Business as Usual," a reference to classic New York hip-hop duo EPMD. And within the large audience of comic book fans, nerds, cosplay enthusiasts, and cartoon aficionados pressed around the pair, there are many young men who know each song by heart, and shout out every lyric.

It's October 2014 and, in the upside-down free-for-all that is modern popular music, one of the hottest hip-hop duos in the United States is made up of a pair of 39-year-olds who've banked off interstitial cartoon music for a rare late-period career renaissance. Not even a second wind, really—maybe a third or fourth. These two are no strangers to critical acclaim, but it's been years since either artist received as much popular attention as they have since officially joining forces last year. "Something special's happening,” El tells me before the boat ride. “There's so much energy, it's ridiculous—me and Mike have tapped into something crazy."