Milo Manheim, Meg Donnelly return in ‘Zombies 3,’ a sci-fi musical with a scosh of horror

Despite being triple-threat teens who could sing, dance and act, Milo Manheim and Meg Donnelly had no clue when they signed on to star in an offbeat, different kind of 2018 Disney high school musical called “Zombies” that four years and one sequel later they’d be in “Zombies 3.”

There were some hints, Manheim, 21, recalled.

“I was doing a musical in high school, a casting agent saw me and this was my first job. But I auditioned like 11 or 12 times. And when we were making it, Chris Scott who choreographed that first one would always say, ‘Just get ready. Just get ready to see your life change after this!’”

“But you don’t know,” added Donnelly, 21, seated next to Manheim for a joint Zoom interview. “I mean, you can guess it’s going to be a success. You can feel it. But it’s hard to really let it sink in until it actually happens.”

What happens in “Zombies 3” begins with Manheim’s Zed, a happy zombie, hoping in his final year at Seabrook High to win a college football scholarship. Donnelly’s Addison, also college-bound but not undead, keeps busy as the town hosts cheer teams from around the world for an ‘international cheer off.’ Then aliens, intergalactic outsiders, arrive to compete and who knows what they really want.

“What is appealing about this zombie franchise,” Manheim said, “is that they’re all so different. They all have such distinct cultures. And to see everybody be harmonious together, see everybody work together in a cause, that’s a really appealing thought.

“And whether it’s consciously or subconsciously, when you’re watching the movie, we see something that brightens up, makes you optimistic. At least that’s how I feel.”

They may be new to starring in Disney musicals but they are showbiz babies. Donnelly started professionally at 5, while Manheim, whose mom is Emmy-winning “The Practice” and “Law & Order” veteran Camryn Manheim, spent years doing school musicals.

“I started in musical theater too like Milo,” Donnelly said. “And since I was 5, I couldn’t see myself doing anything else. I didn’t even know you could really do it as a professional. I was just doing it for fun — and I’m still doing it for fun.”

“I’m so obviously super grateful that I was able to figure out early what I wanted to do,” Manheim agreed. “Being an actor, you get to step into all these different shoes. You get to see from different perspectives and be different people. That has made me a lot more understanding of people, just in my day-to-day life.”

“Zombies 3” streams on Disney+ on July 15.