Disney’s ‘Secret Society of Second-Born Royals’ features princesses, superheroes and action. Now streaming on Disney Plus, the film follows Sam (Peyton Elizabeth Lee), the second-born princess of the kingdom of Illyria. She lives in the shadow of her perfect older sister, Eleanor (Ashley Liao).

Sam is sent to summer school, and discovers she’s actually entered a training program for second-born royals, who each have unique superpowers to help secretly protect their kingdoms. There, she’s joined by fellow second-borns January (Isabella Blake-Thomas), Tuma (Niles Fitch), Roxana (Olivia Deeble) and Matteo (Faly Rakotohavana) to learn from their instructor James (Skylar Astin).

For director Anna Mastro, ensuring the safety of her cast was of upmost importance. Mastro recruited Matt Mullins (“Ford v. Ferrari”) as her trusted stunt coordinator to work with the team and train them in their newfound superpowers.

How did working with a group of kids differ from working with an individual actor?

Matt Mullins: One of the first things I wanted to see was what the kids could actually do. We got the whole cast and said, ‘Alright, what can you guys do?’

The most fun thing is to be able to take everybody’s abilities and see what they’re good at and then highlight that. We also looked at utilizing their personalities to eventually show what their skills were. So, it was a nice discovery process.

We had to come to terms with creating this universe and how to do it safely. Peyton Elizabeth Lee, who plays Sam, rides a skateboard and slides down this rail, so we had to look at how to do it practically. We’d get the stunt team to see what we could do with the actress and where to pad them. Then we’d look at doing a wire shot with the stunt person.

How do you strike that balance of knowing what’s safe for an actor to do and where you need a stunt double, so that you don’t have any broken bones on set?

Anna Mastro: That was exactly why it was important to me to have Matt be a part of the process. We’ve worked together before and I know he’s good at making things look great. I just didn’t trust any other stunt coordinator. You don’t want to hand your kids over to someone you don’t know, so it was important to me to have someone that I could trust on the creative side but to know the kids were going to be safe when they were learning it and training. I knew I could trust him.

How was the chase in the woods scene achieved with the multiple Skylars? 

Mullins: A lot of that was about coming up with James’ abilities. We wanted it to be different and we were trying to find different ways of using the forest.

We had to look at how to pull off Skylar being in 15 places at once, how do we pull it off? We looked at building files and visualizing it. It was about having Skylar in one place, a double there, another guy where we see over his shoulder, and the rest of it was figured out in VFX.

Mastro: We also had a limited amount of time to shoot that sequence. We had from 10 pm to 5 am, and we had to find doubles of Skylar. Every time you see Skylar, he had to go and shoot that scene in that place. It was a process of breaking it down with VFX.

Greg Bryk has done a lot of stunts and had worked with a lot of stunt doubles, but for Skylar, it was the first time he had done physical stunts. He’s done a lot of comedy and romantic comedies, but this was his first time doing action.

Mullins: Skylar came in and rehearsed. If you’re doing one side of a fight, all you have to do is learn that one side, but he had to learn all the different sides and areas because it’s so many different versions against this one guy.

What went into the finale with the battle scene? Was it shot on a real rooftop or was it a mix of both green screen and on-camera stunts?

Mastro: A lot of the ending was in the original script with the guy going down the roof, and it had some great stunt moments. I went to Toronto, and I fell in love with 20 different locations. I went back to Disney and I did a presentation with a photo book of every scene in the movie and it had a photo of what that location would look like, and they went for it.

That rooftop is the real rooftop of that real church. They allowed us to build scaffolding on there, and we added the stairs via green screen, and on the first day, we probably got 95% of the shots we needed. It was such a good thing because the next day, the weather was awful so we would not have been able to get what we did that day.

Mullins: If you do rooftop scenes in New York, they have parapets, but for that rooftop, they didn’t have any safety net, so, we had to put barriers in for safety purposes. And when you’re filming, if the cast was a certain distance to the edge, we had to wire everyone in. There’s a lot to accomplish on the shoot day and add that with all the safety aspects, it’s a lot.