Much of an actor’s job is to convey a character’s inner emotional truth. That can prove complicated when the character requires layers of prosthetics and specialized makeup to come to life. Such was the challenge for Zachary Quinto, who portrays Charlie Manx in AMC’s “NOS4A2,” an adaptation of Joe Hill’s novel about a supernatural being who feeds on the souls of children to replenish his youth. But Quinto had the aid of special makeup designer Joel Harlow, with whom he had collaborated on the “Star Trek” films.

“There are five phases of [Manx’s] aging process,” Quinto says. “We isolated what each of those phases would be, so I was able to adopt specific physical characteristics that would correlate with each one and become progressively more grotesque and decrepit.”

The youngest version of Manx was close to Quinto’s actual age and therefore represented a more real-life look; the oldest was a 135-year-old who was “incredibly closed in, hunched over, really warped,” notes Quinto. In between, the character was depicted at ages 65, 80 and 100.

Harlow says that while extreme elements might be needed for some of the looks, generally “we’re trying to portray realism — otherwise he would just stand out too much.” The makeup artist says Manx is at first trying to charm people: “If he looks like a monster from the beginning, that doesn’t really work.”

To create each version of Manx, Harlow and his team made casts of Quinto, sculpting each stage simultaneously so they could “gauge how much you’re adding to each sculpture.” Once a sculpture was finished, it was broken down into key pieces, including the cheeks, nose, neck, forehead, ears and even hands, with molds fashioned to generate silicone prosthetics.

“Most of the silicone appliances overlap each other in a very specific way so that when you’re finished gluing everything on, it’s a matter of painting and adding contact lenses. The makeup technique is very similar throughout all of the stages,” Harlow explains. “It’s just that the sculptures are different.”

Quinto would shave his face and head at home before arriving to set. Once he got in Harlow’s chair, his skin would be cleaned before they began gluing on the pieces, starting from the neck. “Then you tie it all together with paint, both airbrush and traditional-brush makeup, glue the wig on — and at that point you’re pretty much off to the races,” Harlow says.

The 135-year-old version of Manx allowed Harlow the most creativity because there are no references to real-life people that old. He took some liberties, differing from Hill’s description of the character — most notably by giving Manx hair to offer “a clearer visual representation of his age.”

However, a few elements were plucked directly from the source material: “His teeth are deteriorated, yellowed and broken, as are his fingernails, and they get progressively more so over time,” Harlow says.

In the end, the different stages of Manx’s appearance greatly informed Quinto’s performance.

“I think it’s really important to understand from a psychological perspective … the horrific nature of the trauma he experienced as a child,” says the actor. “If we as human beings don’t deal with trauma … and emotional wounds don’t get healed, they live in places in our bodies. So the oldest versions of Manx are these incredibly twisted and decrepit, locked-in expressions of what he didn’t face and what he didn’t process in his younger life. And he’s always reaching for something outside of himself because he never was able to cultivate a sense of contentment or a sense of fulfillment from within.”