For Joey King, it started with her speaking voice.

To play Gypsy Rose, the young woman in Hulu's The Act whose mom, Dee Dee Blanchard (Patricia Arquette), convinced Gypsy and the world that Gypsy suffered from ailments she didn't actually have, King had to affect the squeaky voice of the real-life Gypsy. Even if Gypsy really was just a sick teenager, her chirpy, saccharine and uncomfortably naïve voice would be unsettling; knowing she's much older than her mom has let on and she's not immobile from leukemia, muscular dystrophy and other diseases however, makes Gypsy's voice deeply unsettling. Per producers request, King didn't use the voice when auditioning for the role but in playing Gypsy, King maintains the young woman's inflection so intensely and so convincingly that one almost expects King to sound like Gypsy when speaking with her, as TV Guide did in early April.

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"Can you imagine if I answered the phone like that?" she said via phone. "You'd be like, 'That poor girl is never going to be cast in anything else."

Joey King, The ActJoey King, The Act

Fair enough. But King's voice is just a brick in the pyramid of her transformative role. She wore prosthetic teeth, she conveyed the singular physical demands of a wheelchair user who later realizes she can walk, and she deftly handled a 180-degree psychological turn from from sweet to sinister. Combined, King's multi-pronged part is an epic metamorphosis with few rivals this season. Shooting lasted five months.

"It was pretty intense," she told TV Guide. "I've never played a character where I had to transform myself so much. Getting in that head space was very dark. I'm not a method actor, so I never stayed in it, but it was so dark going to those places and making yourself think those thoughts and putting yourself in that person's shoes. It is very mentally taxing."

The Act Is Sick and Suspenseful

The Act interprets the true story of the Blanchards' tragedy by starting with Dee Dee's murder, and then methodically untangling how Dee Dee's mental health disorder — Munchausen syndrome by proxy, which is when a caregiver makes up injuries or illnesses for someone — led her dupe health officials, government monitors, neighbors, and Gypsy herself, until Gypsy became wise to her claims and plotted her mother's murder. Macabre by definition, The Act is so chillyitpractically whistles, like a stiff winter wind, its spooky tone established through lighting, color, and moody camera work. Of course, The Act's consistently cold touch gets a boost in continuity from Patricia Arquette, fresh off a handful of awards wins for Escape at Dannemora (which, like The Act, is eligible for the Emmys this year), who keeps her depiction of a woman at the brink of insanity controlled and steady. King impressively holds her own in scenes with the Oscar and Golden Globe winner, giving tense, emotional scenes the grip they need and helping to make the unbelievable story believable.

"I could write an essay about working with Patricia," King said. "She is one of the nicest people, and the best scene partner. I learned so many things from her but trusting your scene partner was one of them. The type of trust we had was so unique and special. We got to the point where we got so close and had so many crazy scenes she told me, 'If you ever think I need another [take] or if I could improve the performance in some way I want you to tell me, because I trust you.' I was like, 'Oh my God, what?' We got to this point where we would tell each other, 'Let's do it again.' It was no judgment, just trust and support, it was so special."

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Patricia Arquette and Joey King, <em>The Act</em>Patricia Arquette and Joey King, The Act

The supportive on-set environment helped King turn some very bizarre material into one of the season's most genuine and haunting portrayals — a role that even the notoriously self-critical actress can look back on with satisfaction.

"As an actor you can only dream of being able to transform yourself and put yourself completely in someone else's shoes and strip away all your ego and vanities...It is one of the first times I've been able to watch a performance of mine and actually be comfortable with telling myself I'm proud of myself."

The Act is streaming on Hulu.