The rumors are true. Or still true.

Bill Murray cameos in the very first episode of Vice Principals, the new Danny McBride-Jody Hill-David Gordon Green “nine-hour epic” coming to HBO this July over two seasons.

And getting Murray to appear in your TV series still requires a bit of lucky timing and the ability to jump through the comedy legend’s peculiar hoops.

Murray doesn’t appear in HBO’s trailer for the series that debuted online Friday, but when they screened the first two episodes in a world premiere event at SXSW in Austin at night, he’s onscreen in a very big way. How’d he agree to do it?

“I’d worked with him twice, on Aloha and Rock the Kasbah — two movies that people loved, everyone that saw both of them,” McBride joked.

That didn’t do the trick, though.

Instead, a chance encounter set things in motion.

When North Carolina — where McBride, Hill and Green all went to film school — came up bust as a shooting location due to taxes, they headed south to scout Charleston to find their fictional “North Jackson High School.”

“We were getting on the plane to fly back to Los Angeles, I just hear someone say my name, and I look over, and Bill was sitting right next to us on the plane that he was flying, by chance,” McBride recalled.

“He took us to see P.F. Chang’s in the Atlanta airport,” he said. “He was just selling us hard on Charleston. He loves it. He lives there. So we came back to shoot there, we were trying to figure out who was going to be Principal Welles, and I was like, ‘Maybe we can try Bill and see if he’d be up for it.’ So I sent him an email. Didn’t know really if he’d respond to it or not, asking him if he’d be interested in checking out the script. He kind of responded — ‘Please deliver me a hard copy at the RiverDogs baseball game tonight.’”

Murray serves as “Director of Fun” as an owner of the Charleston RiverDogs, the Class A affiliate of the New York Yankees.

And McBride famously played Kenny Powers, a baseball pitcher who bounces around the minor leagues in both Carolinas and Mexico in HBO’s Eastbound and Down.

“Alright, alright, we’re in play,” McBride recalled. “I got one of those metal briefcases that people make cocaine deals with, and put the script in there. We came to the RiverDogs game and walked up to his box. I saw there was this commotion. There were people up there. I thought I saw a camera. What is this? You know. And there’s a person standing there with a clipboard, and they’re like, ‘We need to get you mic’d up.’ ‘Mic’d up? What the f**k is this?!’ They put a mic on me and walked me out. It was Bill was out there filming his episode of Anthony Bourdain’s show.”

“I went there, we made the drop-off,” McBride said. “He wrote this really nice e-mail back. ‘I would be thrilled to play Principal Whats-his-name.’ And his only note was…”

Well, I wouldn’t dare spoil that for you.

But it was a great, hilarious note that pays off when you see the scene.

McBride and Walton Goggins star as feuding vice principals at the same South Carolina high school in Vice Principals, which airs its first of two nine-episode seasons this July on HBO.

Sean L. McCarthy works the comedy beat for his own digital newspaper, The Comic’s Comic; before that, for actual newspapers. Based in NYC but will travel anywhere for the scoop: Ice cream or news. He also tweets @thecomicscomic and podcasts half-hour episodes with comedians revealing origin stories: The Comic’s Comic Presents Last Things First.