It’s rare in any show to find actors who have to work quite as closely as James Duncan, Adam Cunningham, and Aaron Haskell. In fact, they play the head, heart, and hindquarters of the same character—working the life-sized title puppet in the Tony–winning hit War Horse. Every subtle move has to be synchronized, from the twitching of the ears to the swishing of the tail, all operated by an elaborate system of cables.

As Duncan puts it in a call over speakerphone from a tour stop in South Dakota: “We like to call it a three-person marriage.” A marriage where the only way you can communicate is via whinnies and nickers.

“Because we’re playing a horse, we can’t talk on-stage. We’re all miked together and we’re responsible for making the animal breathe,” he explains. “That helps you almost understand each other on an instinctive level.”

What’s the prerequisite for playing a horse? Well, other than countless hours spent studying the equine world, this close-knit trio also draw on their diverse backgrounds. Theatre and puppet artist Duncan says it’s the marching-band tours he did as a youth that perhaps most trained him for the kind of focus War Horse demands. Haskell has a background as a puppeteer and dancer, while Cunningham is an actor and a percussionist. “That helps because, once you’re in the horse, you’re moving in the rhythm of a walk or a trot or a gallop,” he says.

What the trio pulls off in the show is something even the author of the original, best-selling War Horse children’s story—Michael Morpurgo—famously said could not be done. To bring to life the moving tale of a boy and his horse during World War I (also told in Steven Spielberg’s 2011 movie of the same name), original directors Marianne Elliott and Tom Morris turned to the South African–based Handspring Puppet Company. The show debuted in London, and has galloped across the world ever since.

What’s said again and again about War Horse’s bent-cane puppets is that audiences forget they aren’t watching the real thing on-stage. They might not be aware, either, of the physical toll the contraptions take: with a person riding above them, the three are sometimes hoisting 77 kilograms (170 pounds) overhead. These guys spend a lot of time in the gym.

It’s hard, but this team seems very Zen when it comes to working as a single being. “Everything is about the movement around you; you have to think like a horse would think,” says Cunningham. “You’re not like a human anymore. I even cough like a horse now!”

War Horse is at the Queen Elizabeth Theatre through Sunday (September 29).