Jimmy Kimmel let David Letterman stroll through his show the way young starstruck directors let Harrison Ford stroll through their sequels. You get where he’s coming from. Kimmel’s living his own private dream this week, like Kramer rebuilding The Merv Griffin Show in his apartment or Seth MacFarlane rebuilding Star Trek on his network. Kimmel’s got Paul Shaffer as a guest bandleader, and he’s broadcasting from New York. Brooklyn, sure, but who can afford Manhattan, and anyhow here came Letterman to complete the fanfiction art project.

Letterman sat down – with a white beard that would’ve said “Old Picard” if it didn’t suddenly say “Old Rick” – and he just became the host of the show, with his own opaque agenda. This was to be expected. Kimmel started the show by re-declaring his fandom for the former Late Show host, saying “David Letterman is to me what Beyoncé is to everyone else.” So he let his hero take the wheel. Letterman ambled in a few tantalizing directions. He mentioned, on a couple occasions, some confusion about how he left Late Show: “I was either fired or retired, I don’t know,” he said, and then later, “Was I fired or retired? It’s still not clear.” Kimmel kept insisting he’d retired. Maybe this was just Letterman playing the cranky oldster, or maybe there was something more there.

Kimmel didn’t pursue the point. He asked Letterman about his new Netflix show, and then happily let his hero glide past any answers. Letterman pretended to think that Netflix was still a DVD-shipping service. He said that it will be some kind of interview show, and he admitted that he’d reached out to Howard Stern for a potential appearance.

Stern is already booked for Kimmel this week, so there’s a hermetic logic to Letterman’s appearance, hosts talking to hosts about how they’ll be talking to other hosts soon. Better example: Letterman took a moment to respond to Conan O’Brien’s strange interview with Stephen Colbert last week. O’Brien told a rambling story about how Letterman gave him a horse, and now Letterman told a rambling story about how the horse was meant as a gag, but O’Brien missed the joke.

“Late Night Host Responds to Late Night Host’s Interview with Late Night Host in Interview with Late Night Host”: The nesting-doll logic is dizzy, a bit thrilling. Late Night Kremlinologists could try to tease out some real resonance from Letterman’s gags. He said he had “nothing but the highest regard for all the talk show men and women, even Jimmy Fallon, I’ll include him.” He couldn’t seem to get over the fact that O’Brien’s wife loved the horse because she was “equestrian.” Then again, maybe best not to dig too deep. Everyone loves to be loved, but you sense that Letterman wants his acolytes to lighten up a bit. Kimmel, sounding endearingly teenaged, revealed that he was wearing a tie Letterman sent to him. Did he miss a joke, too?

You wonder what a real conversation between equals would have sparked. The job Kimmel has now isn’t the job Letterman left two years ago. There’s the internet, which Letterman only ever seemed to barely notice. There’s the explicit politics forefronted in the buzziest late-night monologues. There’s the self-awareness that merely being another white dude in a suit on television can seem like a problem. Hell, now could be a time for some late-night host to ask Letterman about that hindsight-bizarre Gwyneth Paltrow interview that was making the rounds last week.

But maybe that would require a late-night host who didn’t grow up loving Letterman. Instead, the sharpest question of the interview came from the nominal guest. “You’re not thinking about leaving, are you?” Letterman asked Kimmel.

“What, this network?” the younger man responded. “Eventually, sure.”

I loved Kimmel’s nonchalant “eventually,” loved how in the context of late-night time it could mean four years or 40. Kimmel’s my favorite of the current crop of broadcast late-nighters, the five-shows-weekly hosts whose job is so different from week-sharpened Samantha Bee or John Oliver. The machinery around a show like Jimmy Kimmel Live! requires a host to shift from topical humor to filmed sketch to Fifth Harmony intros to weird Google-sponsored advertorials about Kimmel family subway arguments.

And no one looks more relaxed than Kimmel, but you sense the pupil still has something to learn from the master. At one point, Letterman mentioned, in the lead-up to a long shaggy-dog joke about getting directions, that Kimmel has grown a beard. “Are people on you all the time about shaving?” he asked.

“No,” said Kimmel, “They like mine.”

It was a funny line, and Letterman was professional enough to let the laughter build while he made a face of mock annoyance.

“I look like a Civil War statue,” said Letterman.

“There’s talk you might get removed!” Kimmel said, quick again.

“I have been removed,” Letterman said.

It was a funny line, and Paul laughed, and Dave told Paul to stop laughing, and for just a moment we were back with the old gang, us giggling at home the way Kimmel was giggling onscreen. But the weirdest part of that joke was that Letterman hasn’t really been removed. He’ll be back soon on Netflix. Will Kimmel join him there? Eventually, sure.