The “Late Show” host meets an audience ready to exhale and gets a visit from a ranty old friend.

It took Stephen Colbert 15 months to get back in front of a full, live audience telling jokes.

There was a monologue, of course, just as there had been to crowd upon crowd before Colbert and his peers on other networks delivered rushed goodbyes to empty rooms.

But really the monologue wasn’t the big attraction that night, nor, really, was Colbert.

But because Colbert’s “The Late Show” had the biggest audience in late night when it went remote (and rebranded itself “A Late Show”), its reappearance feels like more of a signal event.

But it’s one thing to host the biggest show in late night in front of an adoring crowd and another to do it from your bathtub.

(An extended version of his segment “The Vax Scene” had him go into the crowd with costumed syringe dancers and shimmy with an audience member.).

“The Late Show,” after all, was back back, not in attenuated form but with a full — and vaccinated — audience.

“Being a member of my audience isn’t the only reason to get your shot,” Colbert said.

The segment was charged in a way that it couldn’t have been without a live audience there, in the room.

But also, a lot has changed since Colbert was last in front of a crowd at the Ed Sullivan.

Over his years in front of the CBS audience, Colbert developed a moral authority and cultural soft power, meeting the times with withering sarcasm and sincere emotion

Colbert ended his monologue by bringing onstage his wife, Evie, who had served as his audience surrogate

Turning the job back over to the crowd, she said, “Don’t forget to laugh, because he really needs it.”