Editor’s note: This story first ran Thursday, April 24. The episode aired this weekend.

Legendary late night host David Letterman stunned audience members at Wednesday night’s taping of the long-running TV show “The Nite Show with Danny Cashman” at the Gracie Theater in Bangor when he showed up as the show’s surprise guest.

Letterman is the final guest on the show, which has been airing for 15 years. The episode will air on May 10.

“The Nite Show with Danny Cashman,”  a variety show with opening monologues from host Danny Cashman, interviews, sketches and musical performances, is filmed on the campus of Husson University with help from students and staff of the New England School of Communications.

Letterman has been an inspiration for Cashman, 47, who cites the “The Late Show with David Letterman” host as his No. 1 influence.

Cashman said he’s asked Letterman to be a guest on his show for several years. Letterman’s appearance was finalized in March.

“It was easily the most difficult secret I’ve ever had to keep,” Cashman said Thursday morning.

The two had a brief encounter in 2000 in New York City. Cashman had just left a performance by another legendary talk show host, Jon Stewart, at Carnegie Hall, and was walking by the Ed Sullivan Theater, where “The Late Show with David Letterman” was filmed.

He joined a group of people hoping to catch Letterman as he left the theater. Cashman couldn’t bring himself to ask for a photo with Letterman, but did call out to him as Letterman was getting into a car. Cashman said he can’t remember exactly what he said to Letterman, but it was something about jury duty, a topic Letterman had been joking about for several days on the show.

Letterman heard it, pointed at Cashman and said, “That’s funny.”

It took 25 years for their passing encounter to come full circle.

Cashman said at Wednesday night’s taping somebody mentioned that long-ago exchange to Letterman. “He brought it up on the show, that whole story got told,” Cashman said.

Cashman got emotional talking about what it was like to have his inspiration join him on stage. “When he walked out, I felt my knees start to give out and I just sort of had to crouch and bend over a bit to compose myself,” he said. “I think it was the exuberance of a child on a Tilt-A-Whirl. I couldn’t fathom what has happening.

“I did what I always dreamed of doing, and that’s keeping it together and pulling off what I think is an entertaining piece of television.”

Cashman said that after the Letterman interview, he was able to soak in the gravity of not only having the TV icon as his guest, but also of bidding farewell to the show, as he stood center stage during a lengthy standing ovation.

“The most important thing in the life of this TV show had just happened,” he said.

Cashman said many faces were in the crowd that night, including former teachers, family members, close family friends, people that had worked on the show and Husson University President Lynne Coy-Ogan.

“It was an overwhelmingly emotional moment. And I remember when the applause died down, I couldn’t say anything,” he said.

Along with the May 10 Letterman episode of “The Nite Show,” a few other episodes are left to air.

Special episodes will air on May 11 and 15, with interviews talking about the history and legacy of the show.

On May 17, Cashman ends “The Nite Show” with one final episode, without guests. “We’re trying to take a (Johnny) Carson-esque approach to it, where it’s going to be some memories and highlights and clips and final goodbyes,” he said.

Cashman said that the decision to end “The Nite Show” was driven mostly by a gut feeling. “It felt like the timing is right for us to get done.”

Having Letterman as the final guest was the cherry on top. “There’s no better way I could have written this to conclude,” said Cashman.

The two hosts discussed how it would feel to end such a long-standing part of his life.

“Dave and I talked about that,” he said. “Honestly, that was a big reason, beyond him being my idol, why I wanted him to come on the show because I’m struggling with that, and we talked a lot about that both on camera and off.”

Cashman plans to continue his day job as public relations director of Sutherland-Weston Marketing Communications.

He’ll also continue in his role of board chair of Dirigo Reads, a nonprofit he launched in 2019 with a mission to provide books to first graders in public schools throughout Maine.

“The Nite Show with Danny Cashman” airs on Fox 13 and WGME CBS 13 (Portland), NBC 16 (Presque Isle) and WABI-TV5 (Bangor). For details, visit theniteshowmaine.com.