Residents of Seabrook had to deal with a world where humans and the walking dead didn’t get along in the original Disney+ movie “Zombies.” They worked out their differences but when the second film came along, the town had to face werewolves.

“Zombies 3,” set to debut July 15 on Disney+ and Aug. 12 on Disney Channel, brings a new problem to Seabrook.

Once again, Milo Manheim’s portrayal of zombie Zed and Meg Donnelly’s cheerleader Addison are at the center of all the action (and musical numbers). They thought their biggest problems were finding a way to get Zed into a college that isn’t college friendly and an international cheer-off.

Those take a backseat when a group of aliens in search of a new home world show up and begin searching Seabrook for the key to where they are going. The task of playing the intergalactic travelers with the emotional range of Spock fell to Terry Hu as A-spen, Matt Cornett as A-Ian and Kyra Tantao as A-li.

Just how they were to play visitors from another world took a lot of conversations.

“We took the script and talked about what are the rules of the aliens. What does it look like when we don’t have emotions and when we do have emotions,” Tantao says. “We had so much liberty to bring our own creative process into it.”

The biggest question the three faced was how to find that line between playing a character that would be interesting despite not showing emotions and coming across as just dull. Cornett is certain that the line is so thin that the decision was made to have the aliens stop trying to suppress their emotions early in the film.

Hu took the description of the aliens as being emotionless to such a degree in their first audition tape that they ended up playing the character as being completely lifeless. It was their manager who explained that the character is in a Disney movie and that means even emotionless characters can have some life.

Making sure they found the right tone to play the aliens was very important to the three young actors because they were joining the wildly popular “Zombies” franchise. This is one of the biggest credits for each of them.

Cornett’s previous credits include “High School Musical: The Musical: The Series” while Tantao appeared on “Law & Order: Special Victims Unit.” Hu’s past work includes a series of short films.

Having “Zombies 3” be their biggest acting credit to date made Hu very happy.

“I was not expecting ever to be in a musical,” Hu says. “At the time, I was auditioning a lot and I think it kind of happened. When I booked it, I didn’t think about it being a musical.

“Then I realized it was everything I didn’t think I needed. It really opened up a lot of things for me. I really love dance now and I am brave enough to explore that now.”

Although Cornett came to the project having been in a project before that required him to not only act but also sing and dance. That was a good base for him but he quickly discovered the style of dance was very different in “Zombies 3.”

The dancing he did on “High School Musical: The Musical: The Series” was more theater based. The hip hop and gymnastic elements of “Zombie 3” dancing was a whole new world for Cornett.

“Even though I have danced in other projects, I still had to go and ask for help from the cast members who were part of the first two movies,” Cornett says.

The three actors playing aliens had to deal with playing their roles in a controlled manner. Other cast members got to go in a different direction. Tordjman, whose portrayal of Bucky, Seabrook High’s very self-loving, always over-confident student body president, has been a ball of energy from the first movie. Asked about finding so much enthusiasm to play the role, Tordjman explains it all just comes naturally to him.

“I was born with this much energy,” Tordjman says with great enthusiasm. “My mom ran a dance studio and I think it had something to do with coming up in that environment and just dancing my entire childhood.

“I have always physicalized my energy which I have come to understand can sometimes be overwhelming. But, it works for characters like Bucky.”

Tordjman got some competition for the most energetic member of the case from Carla Jeffery as the super-pumped cheerleader Bree. Jeffery credits her natural positive energy for making the character come across with such great zeal.

Those playing high and low emotions join the rest of the “Zombies 3” cast that also includes Chandler Kinney as Willa, Ariel Martin as Wynter, Pearce Joza as Wyatt, Kylee Russell as Eliza, James Godfrey as Bonzo and Kingston Foster as Zoey.